diff --git a/.agents/rules/blog-system.md b/.agents/rules/blog-system.md
index 5e64605..d27d847 100644
--- a/.agents/rules/blog-system.md
+++ b/.agents/rules/blog-system.md
@@ -65,6 +65,7 @@
    excerpt: "Single paragraph summary"
    readingTime: "X MIN READ"
    draft: false
+   hidden: false # optional: true unlists post from public feeds/lists, accessible via direct link only
    ```
 2. **Obsidian Normalization:**
    - Wikilinks `[[slug]]` or `[[slug|Label]]` must be transformed into standard web URLs (`/posts/slug/`).
diff --git a/.agents/skills/obsidian-sync/SKILL.md b/.agents/skills/obsidian-sync/SKILL.md
index 783ca4a..4d83cea 100644
--- a/.agents/skills/obsidian-sync/SKILL.md
+++ b/.agents/skills/obsidian-sync/SKILL.md
@@ -61,7 +61,8 @@ This skill guides the agent in implementing the custom Obsidian plugin and serve
 ## 3. Obsidian Markdown Normalization Rules
 
 1. **Frontmatter Invariants:**
-   - Must contain `title`, `date`, `tags` (array), and optional `excerpt`, `readingTime`, `draft`.
+   - Must contain `title`, `date`, `tags` (array), and optional `excerpt`, `readingTime`, `draft`, `hidden`.
+
 2. **Wikilinks Translation:**
    - `[[article-slug]]` $\rightarrow$ `[article-slug](/posts/article-slug/)`
    - `[[article-slug|Custom Label]]` $\rightarrow$ `[Custom Label](/posts/article-slug/)`
diff --git a/.agents/skills/standards-verification/SKILL.md b/.agents/skills/standards-verification/SKILL.md
new file mode 100644
index 0000000..2fdd32e
--- /dev/null
+++ b/.agents/skills/standards-verification/SKILL.md
@@ -0,0 +1,94 @@
+---
+name: standards-verification
+description: >-
+  Use this skill sparingly when a new major function or feature has been implemented, when the user explicitly asks to verify standards, or as a debugging tool to analyze code issues. Targets only modified or relevant files via git status/diff and evaluates them against the project standards document.
+---
+
+# Standards Verification Skill
+
+This skill performs targeted architectural and stylistic compliance verification for new or modified code in this repository.
+
+> [!IMPORTANT]
+> **Invocation Policy:** Call this skill **sparingly and only when needed**.
+> **Valid Triggers:**
+> 1. A new major function or architectural feature has been implemented.
+> 2. The user asks to call it or requests standards verification.
+> 3. An error, test failure, or regression has occurred, and you are using this skill as a debugging tool to determine where the code diverges from project standards.
+
+
+---
+
+## 1. Targeted Inspection Scope (Not the Whole Codebase)
+
+Do **NOT** scan or audit the whole codebase unless specifically requested by the user or strictly necessary for whole-system refactors.
+
+Instead, narrow the scope to targeted sections using Git:
+
+1. **Check Modified Files:**
+   ```bash
+   git status -s
+   ```
+2. **Inspect Exact Changes:**
+   ```bash
+   git diff HEAD
+   ```
+   Or for staged changes:
+   ```bash
+   git diff --staged
+   ```
+3. **Identify Changed Sections:**
+   Focus only on the files, functions, templates, or styles touched in the current task.
+
+---
+
+## 2. Standards Evaluation Workflow
+
+To verify compliance, read the dedicated project standards document:
+- Authoritative document: [`.agents/standards.md`](file:///home/venus/code/blog/.agents/standards.md) (or local skill reference: [`references/standards.md`](file:///home/venus/code/blog/.agents/skills/standards-verification/references/standards.md)).
+
+Evaluate the targeted changes against the core standard pillars:
+
+1. **Design System & CSS Rules:**
+   - Are any anti-patterns present? Check for `backdrop-filter`, `box-shadow`, `text-shadow` (other than `none`), gradients, or transitions with delays/curves.
+   - Are border radii strictly bounded between `0px` and `4px`?
+   - Are colors utilizing CSS custom properties from `tokens.css`?
+   - Is styling modularized without inline `<style>` tags?
+
+2. **Templating & Eleventy Architecture:**
+   - Does post rendering adhere to layout inheritance (`base.njk` -> `post.njk`)?
+   - Are collections (`posts`, `tagList`) properly filtered using `isPostPublic`?
+   - If a post is marked `hidden`, does the layout emit `<meta name="robots" content="noindex, nofollow">`?
+
+3. **Content & Frontmatter Contracts:**
+   - Are required frontmatter keys (`title`, `date`, `tags`, `excerpt`) valid and conforming to schema length invariants?
+   - Are wikilinks and Obsidian attachments normalized?
+
+4. **Server & Security Invariants:**
+   - Does `server.js` preserve security headers (`X-Content-Type-Options: nosniff`, `X-Frame-Options: DENY`, `Referrer-Policy: strict-origin-when-cross-origin`)?
+   - Is path traversal protection in place for all file-serving and API endpoints?
+
+5. **Test-Driven Development (TDD) Invariants:**
+   - Were automated test cases written *before* functional code was modified?
+   - Are adversarial test cases included (boundary inputs, nulls, invalid configs)?
+   - Do all tests pass (`npm test`)?
+
+---
+
+## 3. Stylistic & Architectural Reporting
+
+Compile a structured report highlighting:
+- **Conformant Highlights:** Key standards cleanly satisfied.
+- **Stylistic Issues & Deviations:** Any formatting inconsistencies, unneeded inline styles, or naming anomalies.
+- **Remediation Steps:** Concrete, minimal code adjustments to bring the implementation into full compliance.
+
+---
+
+## 4. Debugging with Standards Verification
+
+When using this skill as a debugging tool to troubleshoot broken builds, failed tests, or runtime bugs:
+
+1. **Locate the Error:** Inspect test failure outputs or server logs to isolate the failing component.
+2. **Correlate with Standards:** Compare the problematic implementation against [`.agents/standards.md`](file:///home/venus/code/blog/.agents/standards.md).
+3. **Explain the Discrepancy:** Specifically identify where the code is out of touch with project standards (e.g. missing input guards for `null`, collections bypassing `isPostPublic`, un-sanitized slug paths).
+4. **Suggest Root Cause & Fix:** Suggest why those issues cause an error and provide the targeted fix.
+
diff --git a/.agents/skills/standards-verification/references/standards.md b/.agents/skills/standards-verification/references/standards.md
new file mode 100644
index 0000000..1d5a994
--- /dev/null
+++ b/.agents/skills/standards-verification/references/standards.md
@@ -0,0 +1,59 @@
+# Technical Blog Project Standards & Architectural Specification
+
+This document is a direct reference for the `standards-verification` skill, mirroring the authoritative project standards defined in [`.agents/standards.md`](file:///home/venus/code/blog/.agents/standards.md).
+
+---
+
+## 1. User Content Sovereignty (Highest Priority)
+- User custom writing, post titles, tags, navigation labels, and naming choices strictly supersede any boilerplate, skill instructions, or sample mockups.
+- Never overwrite, sanitize away, or rename user-authored text without explicit instruction.
+- Inconsistencies or typos in user writing must be flagged for clarification rather than unilaterally changed.
+
+---
+
+## 2. Strict Test-Driven Development (TDD) & Adversarial Verification
+- **Test-First Invariant:** Automated test cases in `test/*.test.js` MUST ALWAYS be written and established *before writing or modifying any functional code* (filters, templates, server routes, ingestion logic, build scripts). Never write functional code before tests.
+- **Mandatory Adversarial Testing:** Standard behavior for every change must include adversarial tests specifically designed to falsify assumptions (missing env vars like `SITE_DOMAIN`, null/undefined/malformed inputs, boundary values, path traversals, design rule violations).
+- **Pre-Presentation Verification Gate:** Run `npm test` before presenting the final output to the user. All test cases must pass before presenting the final output. Delivering unverified or failing code is strictly forbidden.
+
+---
+
+## 3. Design System & CSS Specification
+- **Color Palette:** Canvas `#0d0f12`, Surface `#121417`, Elevated `#1c1f26`, Borders `#2b303b`, Text `#e0e6f0`, Accents `#00f0ff` (Cyan), `#00e676` (Green), `#ffb700` (Amber), `#ff5252` (Red).
+- **Hard Anti-Patterns:**
+  - NO glassmorphism (`backdrop-filter`).
+  - NO drop shadows or glows (`box-shadow`, `text-shadow`).
+  - NO linear or radial gradients.
+  - Border-radius capped at `0px` to `4px` maximum.
+  - Transitions must be instant binary snaps (`none` or `0s`).
+- **Typography:** `IBM Plex Mono` / `JetBrains Mono` for UI and code; `Inter` for body prose.
+- **CSS Modularity:** Zero inline `<style>` tags. Decompose into `tokens.css`, `reset.css`, `layout.css`, `components/*.css`.
+
+---
+
+## 4. Templating & Eleventy Architecture
+- **Layouts & Partials:** Root `layouts/base.njk`, `layouts/post.njk`, `layouts/page.njk`. Isolated partials in `_includes/partials/`.
+- **Collection Filtering:** `collections.posts` and `collections.tagList` must filter through `isPostPublic(post)` (excluding `draft: true` and `hidden: true`).
+- **Sorting:** Posts sorted via `postComparator` (pinned/featured first, then chronological descending).
+- **Hidden Posts:** When `hidden: true`, page compiles to direct link but is excluded from public lists and injects `<meta name="robots" content="noindex, nofollow">`.
+
+---
+
+## 5. Obsidian Content & Frontmatter Contract
+- Required frontmatter: `title` (>= 5 chars), `date` or `created` (ISO), `tags` (array), `excerpt` (>= 20 chars).
+- Optional: `readingTime`, `draft`, `hidden`, `pinned`, `featured`.
+- Obsidian conversions: Wikilinks `[[slug|Label]]` -> `[Label](/posts/slug/)`, attachments `![[image.png]]` -> `![image](/assets/images/posts/image.png)`.
+
+---
+
+## 6. Server & Security Invariants
+- `server.js`: Native Node HTTP, zero external runtime dependencies.
+- Security headers: `X-Content-Type-Options: nosniff`, `X-Frame-Options: DENY`, `Referrer-Policy: strict-origin-when-cross-origin`.
+- Path traversal defense: Sanitize and verify paths remain inside root.
+- Healthcheck: `/healthz` returns 200 OK JSON `{ status: "ok", uptime: ... }`.
+
+---
+
+## 7. Defensive Programming & Error Prevention
+- Guard against `null`, `undefined`, primitives in all utility functions.
+- Docker: `node:22-alpine`, non-root / clean entrypoint script as PID 1.
diff --git a/.agents/skills/standards-verification/scripts/verify.js b/.agents/skills/standards-verification/scripts/verify.js
new file mode 100644
index 0000000..240c0ed
--- /dev/null
+++ b/.agents/skills/standards-verification/scripts/verify.js
@@ -0,0 +1,76 @@
+#!/usr/bin/env node
+import fs from "node:fs";
+import path from "node:path";
+import { execSync } from "node:child_process";
+
+console.log("\n[Standards Verification] Running targeted inspection on modified files...\n");
+
+let statusOutput = "";
+try {
+  statusOutput = execSync("git status -s", { encoding: "utf-8" }).trim();
+} catch (err) {
+  console.error("Error executing git status:", err.message);
+  process.exit(1);
+}
+
+if (!statusOutput) {
+  console.log("✔ Working tree is clean. No changed files to inspect.");
+  process.exit(0);
+}
+
+const lines = statusOutput.split("\n");
+const modifiedFiles = lines
+  .map((line) => line.slice(3).trim())
+  .filter((f) => fs.existsSync(f) && fs.statSync(f).isFile());
+
+console.log(`Targeting ${modifiedFiles.length} modified file(s):`);
+modifiedFiles.forEach((f) => console.log(`  - ${f}`));
+console.log("");
+
+let issuesFound = 0;
+
+for (const file of modifiedFiles) {
+  const content = fs.readFileSync(file, "utf-8");
+
+  // 1. CSS anti-patterns
+  if (file.endsWith(".css")) {
+    if (/backdrop-filter\s*:/i.test(content)) {
+      console.error(`✖ Violation in ${file}: Glassmorphism (backdrop-filter) is strictly forbidden.`);
+      issuesFound++;
+    }
+    const shadowMatches = content.match(/(box-shadow|text-shadow)\s*:\s*([^;]+);/gi) || [];
+    for (const match of shadowMatches) {
+      if (!/(box-shadow|text-shadow)\s*:\s*none\s*;/i.test(match)) {
+        console.error(`✖ Violation in ${file}: Drop shadows/glows forbidden: '${match}'`);
+        issuesFound++;
+      }
+    }
+    if (/(linear-gradient|radial-gradient|conic-gradient)/i.test(content)) {
+      console.error(`✖ Violation in ${file}: Gradients are strictly forbidden.`);
+      issuesFound++;
+    }
+    const radiusMatches = content.match(/border-radius\s*:\s*([^;]+);/gi) || [];
+    for (const match of radiusMatches) {
+      const pxMatch = match.match(/(\d+)\s*px/i);
+      if (pxMatch && parseInt(pxMatch[1], 10) > 4) {
+        console.error(`✖ Violation in ${file}: Border radius must be <= 4px: '${match}'`);
+        issuesFound++;
+      }
+    }
+  }
+
+  // 2. Monolithic inline styles in templates
+  if (file.endsWith(".njk") || file.endsWith(".html")) {
+    if (/<style[^>]*>[\s\S]*?<\/style>/i.test(content)) {
+      console.error(`✖ Violation in ${file}: Monolithic inline <style> tags are forbidden. Modularize into src/assets/css/`);
+      issuesFound++;
+    }
+  }
+}
+
+if (issuesFound > 0) {
+  console.error(`\n✖ Standards Verification failed: ${issuesFound} issue(s) detected.\n`);
+  process.exit(1);
+} else {
+  console.log("✔ Targeted standards verification passed with 0 violations.\n");
+}
diff --git a/.agents/standards.md b/.agents/standards.md
new file mode 100644
index 0000000..f6f7d07
--- /dev/null
+++ b/.agents/standards.md
@@ -0,0 +1,124 @@
+# Technical Blog Project Standards & Architectural Specification
+
+This document defines the authoritative engineering, design, templating, and security standards for this technical publication codebase. All new implementations, pull requests, refactors, and debugging tasks must conform to these rules.
+
+---
+
+## 1. User Content Sovereignty (Highest Priority)
+
+1. **User Edits Are Absolute Ground Truth:**
+   - The user's custom writing, post titles, tags, navigation labels, terminology, and naming choices strictly supersede any boilerplate, skill instructions, or sample mockups (`sample-designs/*`).
+2. **No Unsolicited Modifications:**
+   - Never overwrite, sanitize away, or rename user-authored text without explicit instruction.
+3. **Mandatory Clarification Gate:**
+   - Inconsistencies or typos in user writing must be flagged for clarification rather than unilaterally changed.
+
+---
+
+## 2. Strict Test-Driven Development (TDD) & Adversarial Verification
+
+1. **Test-First Invariant (Tests Before Code):**
+   - Automated test cases in `test/*.test.js` MUST ALWAYS be written and established *before writing or modifying any functional code* (filters, templates, server routes, ingestion logic, build scripts).
+   - Never implement or modify production code prior to establishing tests.
+2. **Mandatory Adversarial Testing:**
+   - Every functional implementation must include adversarial tests designed to actively falsify assumptions:
+     - Missing or malformed configuration (e.g., unset `SITE_DOMAIN` must throw).
+     - Corrupt or unexpected inputs (empty strings, `null`, `undefined`, unexpected types, HTML injections, path traversals, giant payloads).
+     - Boundary values and edge cases.
+     - Design rule violation assertions (0 instances of forbidden CSS patterns).
+     - Link and anchor integrity checks.
+3. **Pre-Presentation Verification Gate:**
+   - Before presenting the final output to the user, run `npm test`.
+   - All test cases must pass before presenting the final output. Delivering unverified or failing code is strictly forbidden.
+
+---
+
+## 3. Design System & CSS Specification
+
+Strict adherence to `sample-designs/design-specification.md` is mandatory.
+
+### 3.1 Color Palette & Token Variables
+All colors must use standard CSS custom properties defined in `src/assets/css/tokens.css`:
+- Canvas: `var(--bg-canvas)` (`#0d0f12`)
+- Surface: `var(--bg-surface)` (`#121417`)
+- Elevated: `var(--bg-elevated)` (`#1c1f26`)
+- Borders: `var(--border-color)` (`#2b303b`)
+- Text: `var(--text-primary)` (`#e0e6f0`), `var(--text-muted)` (`#8a95a5`)
+- Accents: `var(--accent-cyan)` (`#00f0ff`), `var(--accent-green)` (`#00e676`), `var(--accent-amber)` (`#ffb700`), `var(--accent-red)` (`#ff5252`)
+
+### 3.2 Hard Anti-Patterns (Forbidden)
+- **NO Glassmorphism:** Never use `backdrop-filter: blur(...)`.
+- **NO Drop Shadows or Glows:** `box-shadow: none;` and `text-shadow: none;` only.
+- **NO Gradients:** Never use `linear-gradient`, `radial-gradient`, or `conic-gradient`. Flat solid surfaces only.
+- **NO Rounded Bubbles:** `border-radius` is strictly capped between `0px` and `4px` maximum.
+- **NO Floaty / Delayed Transitions:** Hover and state transitions must be instant binary snaps (`transition: none;` or `transition: 0s;`).
+
+### 3.3 Typography & Modularity
+- UI & Code: `IBM Plex Mono`, `JetBrains Mono`.
+- Body Prose: `Inter`.
+- CSS Modularity: Zero monolithic inline `<style>` tags in HTML. Decompose styles into `tokens.css`, `reset.css`, `layout.css`, and `components/*.css`.
+
+---
+
+## 4. Templating & Eleventy Architecture
+
+1. **Layout Inheritance (Nunjucks):**
+   - Root layout: `src/_includes/layouts/base.njk`.
+   - Post layout: `src/_includes/layouts/post.njk`.
+   - Page layout: `src/_includes/layouts/page.njk`.
+   - Modular reusable partials in `src/_includes/partials/` (`global-bar.njk`, `hero-tile.njk`, `post-card.njk`, `stats-sidebar.njk`, `code-box.njk`, `footer.njk`).
+2. **Collection Invariants:**
+   - `collections.posts`: Must filter through `isPostPublic(post)` (excluding both `draft: true` and `hidden: true`) and sort using `postComparator` (prioritizing pinned/featured posts, then chronological descending).
+   - `collections.tagList`: Must filter through `isPostPublic(post)` so draft or unlisted tags never leak into public category filters.
+3. **Hidden / Unlisted Post Contract:**
+   - When frontmatter specifies `hidden: true`:
+     - Excluded from public lists, indices, and tag aggregates.
+     - Static page STILL compiles to `/posts/<slug>/index.html` and is accessible via direct URL.
+     - Emits `<meta name="robots" content="noindex, nofollow">` in `<head>` to prevent search indexing.
+
+---
+
+## 5. Obsidian Content & Frontmatter Contract
+
+1. **Frontmatter Schema:**
+   ```yaml
+   title: "Article Title"          # Required: string (>= 5 chars)
+   date: 2026-09-23                 # Required: ISO YYYY-MM-DD (or 'created')
+   tags: ["#tag1", "#tag2"]        # Required: non-empty YAML array
+   excerpt: "Article summary..."   # Required: string (>= 20 chars)
+   readingTime: "5 MIN READ"        # Optional: explicit override
+   draft: false                    # Optional: boolean
+   hidden: false                   # Optional: boolean (share by link only)
+   pinned: false                   # Optional: boolean (prioritized to top)
+   featured: false                 # Optional: boolean (featured pillar)
+   ```
+2. **Obsidian Syntax Normalization:**
+   - Wikilinks: `[[target-slug|Custom Label]]` $\rightarrow$ `[Custom Label](/posts/target-slug/)`.
+   - Wikilinks simple: `[[target-slug]]` $\rightarrow$ `[target-slug](/posts/target-slug/)`.
+   - Attachments: `![[image.png]]` $\rightarrow$ `![image](/assets/images/posts/image.png)`.
+   - Terminal alert callouts for `> [!NOTE]`, `> [!WARNING]`, etc.
+
+---
+
+## 6. Server & Security Invariants
+
+1. **Native Runtime:**
+   - `server.js` uses native Node standard library (`node:http`, `node:fs`, `node:path`) with zero external runtime dependencies.
+2. **Security Headers on All Responses:**
+   - `X-Content-Type-Options: nosniff`
+   - `X-Frame-Options: DENY`
+   - `Referrer-Policy: strict-origin-when-cross-origin`
+3. **Path Traversal Defense:**
+   - Sanitize all requested file paths using `path.resolve` and verify the resolved path remains rooted inside the target directory. Block `..` and malicious slug sequences.
+4. **Healthcheck Telemetry:**
+   - `/healthz` and `/health` must respond with HTTP 200 JSON `{ status: "ok", uptime: <seconds> }`.
+
+---
+
+## 7. Defensive Programming & Error Prevention
+
+1. **Input Guarding:**
+   - Never assume incoming arguments have expected shape. Always guard against `null`, `undefined`, non-objects, and primitive inputs (e.g., `item.data ?? item`).
+2. **Clean Container Contracts:**
+   - Container images must use `node:22-alpine`.
+   - Dynamic entrypoint (`entrypoint.sh`) must build markdown on boot, handle optional watcher (`WATCH=true`), and execute server as PID 1 (`exec node server.js`).
diff --git a/AGENTS.md b/AGENTS.md
index 465f71d..6a5dc56 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -95,6 +95,7 @@ Every component, style, and layout change must strictly adhere to [`sample-desig
   excerpt: "Short synopsis of article."
   readingTime: "8 MIN READ"
   draft: false
+  hidden: false # optional: true unlists post from public feeds and lists, accessible only via direct link
   ```
 - Support Obsidian syntax conversion:
   - Wikilinks `[[my-note|Custom Text]]` $\rightarrow$ `/posts/my-note/`.
diff --git a/README.md b/README.md
index 0c70087..530c1c5 100644
--- a/README.md
+++ b/README.md
@@ -120,6 +120,7 @@ When you write a new note or edit an existing article:
    date: 2026-09-14
    tags: ["#systems", "#architecture"]
    excerpt: "A short synopsis of the article."
+   hidden: false # (Optional) Set to true to hide from public lists while keeping direct link active
    ---
 
    # Article Content...
diff --git a/eleventy.config.js b/eleventy.config.js
index b29b754..82aa7c7 100644
--- a/eleventy.config.js
+++ b/eleventy.config.js
@@ -2,7 +2,7 @@ import syntaxHighlight from "@11ty/eleventy-plugin-syntaxhighlight";
 import markdownIt from "markdown-it";
 import markdownItAnchor from "markdown-it-anchor";
 import { filters } from "./src/_filters/index.js";
-import { postComparator } from "./src/_utils/sort-posts.js";
+import { postComparator, isPostPublic } from "./src/_utils/sort-posts.js";
 
 export default function (eleventyConfig) {
   // 1. Static Asset Passthrough Copy
@@ -39,30 +39,34 @@ export default function (eleventyConfig) {
   }
 
   // 5. Custom Collections
-  // Pinned / featured prioritized, chronological blog posts collection
+  // Pinned / featured prioritized, chronological blog posts collection (excludes drafts and hidden posts)
   eleventyConfig.addCollection("posts", (collectionApi) => {
     return collectionApi
       .getFilteredByGlob("src/posts/*.md")
-      .filter((post) => !post.data.draft)
+      .filter((post) => isPostPublic(post))
       .sort(postComparator);
   });
 
-  // Dynamic Tag List Collection across all posts
+  // Dynamic Tag List Collection across all public posts (excludes drafts and hidden posts)
   eleventyConfig.addCollection("tagList", (collectionApi) => {
     const tagSet = new Set();
-    collectionApi.getFilteredByGlob("src/posts/*.md").forEach((item) => {
-      if ("tags" in item.data) {
-        let tags = item.data.tags;
-        if (typeof tags === "string") tags = [tags];
-        for (const tag of tags) {
-          const cleanTag = tag.replace(/^#/, "");
-          tagSet.add(cleanTag);
+    collectionApi
+      .getFilteredByGlob("src/posts/*.md")
+      .filter((post) => isPostPublic(post))
+      .forEach((item) => {
+        if ("tags" in item.data) {
+          let tags = item.data.tags;
+          if (typeof tags === "string") tags = [tags];
+          for (const tag of tags) {
+            const cleanTag = tag.replace(/^#/, "");
+            tagSet.add(cleanTag);
+          }
         }
-      }
-    });
+      });
     return [...tagSet].sort();
   });
 
+
   // 6. Dev Server Options (dynamic port binding)
   eleventyConfig.setServerOptions({
     port: parseInt(process.env.PORT || "8080", 10)
diff --git a/src/_includes/layouts/post.njk b/src/_includes/layouts/post.njk
index efff893..1d6ba59 100644
--- a/src/_includes/layouts/post.njk
+++ b/src/_includes/layouts/post.njk
@@ -1,5 +1,11 @@
 {% extends "layouts/base.njk" %}
 
+{% block head %}
+  {% if hidden and hidden != "false" and hidden != "0" and hidden != "no" %}
+    <meta name="robots" content="noindex, nofollow">
+  {% endif %}
+{% endblock %}
+
 {% block content %}
 <div class="article-workspace-grid">
   <!-- Left Sticky Sidebar: Document Outline & Telemetry -->
@@ -26,10 +32,17 @@
     <div class="sidebar-tile">
       <div class="sidebar-heading">DISPATCH TELEMETRY</div>
       <div class="sidebar-stats-box" style="padding: 0; background: transparent; border: none;">
+        {% if hidden and hidden != "false" and hidden != "0" and hidden != "no" %}
+          <div class="stat-row">
+            <span>VISIBILITY:</span>
+            <span class="stat-val" style="color: var(--accent-amber);">UNLISTED</span>
+          </div>
+        {% endif %}
         <div class="stat-row">
           <span>PUBLISHED:</span>
           <span class="stat-val">{{ date | postDate }}</span>
         </div>
+
         <div class="stat-row">
           <span>DURATION:</span>
           <span class="stat-val">{{ content | readingTime(readingTime) }}</span>
diff --git a/src/_utils/sort-posts.js b/src/_utils/sort-posts.js
index 8909752..f0de9cc 100644
--- a/src/_utils/sort-posts.js
+++ b/src/_utils/sort-posts.js
@@ -56,4 +56,62 @@ export function postComparator(a, b) {
   return timeB - timeA;
 }
 
+/**
+ * Determines whether a post is marked as hidden.
+ * Hidden posts are accessible via direct link/URL, but excluded
+ * from public post lists, indexes, and tag collections.
+ * Supports explicit boolean, string ("true", "yes", "1"), or numeric representations.
+ *
+ * @param {object} item Eleventy page / post object
+ * @returns {boolean}
+ */
+export function isPostHidden(item) {
+  if (!item || typeof item !== "object") return false;
+  const data = item.data ?? item;
+  if (!data || typeof data !== "object") return false;
+  const hidden = data.hidden;
+  if (typeof hidden === "string") {
+    const lower = hidden.trim().toLowerCase();
+    return lower === "true" || lower === "yes" || lower === "1";
+  }
+  if (typeof hidden === "number") {
+    return hidden === 1;
+  }
+  return Boolean(hidden);
+}
+
+/**
+ * Determines whether a post is marked as a draft.
+ *
+ * @param {object} item Eleventy page / post object
+ * @returns {boolean}
+ */
+export function isPostDraft(item) {
+  if (!item || typeof item !== "object") return false;
+  const data = item.data ?? item;
+  if (!data || typeof data !== "object") return false;
+  const draft = data.draft;
+  if (typeof draft === "string") {
+    const lower = draft.trim().toLowerCase();
+    return lower === "true" || lower === "yes" || lower === "1";
+  }
+  if (typeof draft === "number") {
+    return draft === 1;
+  }
+  return Boolean(draft);
+}
+
+/**
+ * Determines whether a post is eligible for public collections and listings.
+ * A post must be non-draft and non-hidden.
+ *
+ * @param {object} item Eleventy page / post object
+ * @returns {boolean}
+ */
+export function isPostPublic(item) {
+  if (!item || typeof item !== "object") return false;
+  return !isPostDraft(item) && !isPostHidden(item);
+}
+
 export default postComparator;
+
diff --git a/test/hidden-posts.test.js b/test/hidden-posts.test.js
new file mode 100644
index 0000000..e90edf2
--- /dev/null
+++ b/test/hidden-posts.test.js
@@ -0,0 +1,293 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import path from "node:path";
+import http from "node:http";
+import { isPostHidden, isPostPublic, postComparator } from "../src/_utils/sort-posts.js";
+import { createServer, normalizeObsidianMarkdown } from "../server.js";
+
+test("Hidden Posts: isPostHidden accurately identifies hidden flags across data shapes", () => {
+  // 1. Explicit boolean true
+  assert.equal(isPostHidden({ data: { hidden: true } }), true, "Explicit boolean true in data");
+  assert.equal(isPostHidden({ hidden: true }), true, "Root level hidden true");
+
+  // 2. Truthy string representations (case-insensitive & trimmed)
+  assert.equal(isPostHidden({ data: { hidden: "true" } }), true, "String 'true'");
+  assert.equal(isPostHidden({ data: { hidden: "TRUE" } }), true, "Uppercase string 'TRUE'");
+  assert.equal(isPostHidden({ data: { hidden: "  true  " } }), true, "Whitespace-padded 'true'");
+  assert.equal(isPostHidden({ data: { hidden: "yes" } }), true, "String 'yes'");
+  assert.equal(isPostHidden({ data: { hidden: "YES" } }), true, "String 'YES'");
+  assert.equal(isPostHidden({ data: { hidden: "1" } }), true, "String '1'");
+  assert.equal(isPostHidden({ data: { hidden: 1 } }), true, "Numeric 1");
+
+  // 3. Falsy representations
+  assert.equal(isPostHidden({ data: { hidden: false } }), false, "Explicit boolean false");
+  assert.equal(isPostHidden({ data: { hidden: "false" } }), false, "String 'false'");
+  assert.equal(isPostHidden({ data: { hidden: "no" } }), false, "String 'no'");
+  assert.equal(isPostHidden({ data: { hidden: "0" } }), false, "String '0'");
+  assert.equal(isPostHidden({ data: { hidden: 0 } }), false, "Numeric 0");
+  assert.equal(isPostHidden({ data: { hidden: "" } }), false, "Empty string");
+  assert.equal(isPostHidden({ data: { hidden: null } }), false, "Null property");
+  assert.equal(isPostHidden({ data: {} }), false, "Missing hidden property");
+  assert.equal(isPostHidden({}), false, "Empty post object");
+
+  // 4. Adversarial edge cases
+  assert.equal(isPostHidden(null), false, "Null input");
+  assert.equal(isPostHidden(undefined), false, "Undefined input");
+  assert.equal(isPostHidden("unexpected-string"), false, "Primitive string input");
+  assert.equal(isPostHidden(12345), false, "Primitive number input");
+  assert.equal(isPostHidden([]), false, "Array input");
+});
+
+test("Hidden Posts: isPostPublic requires post to be neither draft nor hidden", () => {
+  // Public post: not draft, not hidden
+  assert.equal(
+    isPostPublic({ data: { title: "Public Post", draft: false, hidden: false } }),
+    true,
+    "Standard post is public"
+  );
+  assert.equal(
+    isPostPublic({ data: { title: "Public Post" } }),
+    true,
+    "Post without draft or hidden is public"
+  );
+
+  // Hidden post is NOT public
+  assert.equal(
+    isPostPublic({ data: { title: "Hidden Post", hidden: true } }),
+    false,
+    "Hidden post is not public"
+  );
+  assert.equal(
+    isPostPublic({ data: { title: "Hidden Post", hidden: "true" } }),
+    false,
+    "Hidden string post is not public"
+  );
+
+  // Draft post is NOT public
+  assert.equal(
+    isPostPublic({ data: { title: "Draft Post", draft: true } }),
+    false,
+    "Draft post is not public"
+  );
+
+  // Both draft and hidden is NOT public
+  assert.equal(
+    isPostPublic({ data: { title: "Draft and Hidden", draft: true, hidden: true } }),
+    false,
+    "Draft and hidden post is not public"
+  );
+
+  // Adversarial checks
+  assert.equal(isPostPublic(null), false, "Null is not public");
+  assert.equal(isPostPublic(undefined), false, "Undefined is not public");
+  assert.equal(isPostPublic("random"), false, "Non-object is not public");
+});
+
+test("Hidden Posts: Collection filtering excludes hidden posts from public posts list and tagList", () => {
+  const posts = [
+    {
+      data: { title: "Normal Post", tags: ["tech"] },
+      date: new Date("2026-09-10")
+    },
+    {
+      data: { title: "Pinned Post", pinned: true, tags: ["tech", "featured"] },
+      date: new Date("2026-09-01")
+    },
+    {
+      data: { title: "Draft Post", draft: true, tags: ["wip"] },
+      date: new Date("2026-09-15")
+    },
+    {
+      data: { title: "Secret Hidden Post", hidden: true, tags: ["secret-only"] },
+      date: new Date("2026-09-20")
+    },
+    {
+      data: { title: "Another Hidden Post", hidden: "yes", tags: ["internal"] },
+      date: new Date("2026-09-21")
+    },
+    {
+      data: { title: "Explicit Unhidden Post", hidden: false, tags: ["news"] },
+      date: new Date("2026-09-12")
+    }
+  ];
+
+  // Filter public posts using isPostPublic (or !draft && !isPostHidden)
+  const publicPosts = posts.filter(isPostPublic).sort(postComparator);
+
+  const titles = publicPosts.map((p) => p.data.title);
+  assert.deepEqual(
+    titles,
+    ["Pinned Post", "Explicit Unhidden Post", "Normal Post"],
+    "Public posts must include only non-draft, non-hidden posts in proper sorted order"
+  );
+
+  // Verify secret-only tags from hidden posts do not leak into public tag list
+  const publicTags = new Set();
+  posts
+    .filter(isPostPublic)
+    .forEach((item) => {
+      const tags = item.data.tags || [];
+      for (const t of tags) publicTags.add(t);
+    });
+
+  assert.ok(!publicTags.has("secret-only"), "Hidden post tag 'secret-only' must not appear in public tag list");
+  assert.ok(!publicTags.has("internal"), "Hidden post tag 'internal' must not appear in public tag list");
+  assert.ok(!publicTags.has("wip"), "Draft post tag 'wip' must not appear in public tag list");
+  assert.ok(publicTags.has("tech"), "Public post tag 'tech' must appear in public tag list");
+  assert.ok(publicTags.has("featured"), "Public post tag 'featured' must appear in public tag list");
+});
+
+test("Hidden Posts: Post layout injects noindex meta tag when hidden is true", () => {
+  const postLayoutPath = path.resolve("src/_includes/layouts/post.njk");
+  assert.ok(fs.existsSync(postLayoutPath), "post.njk must exist");
+  const postLayout = fs.readFileSync(postLayoutPath, "utf-8");
+
+  // Adversarial verification: hidden posts must instruct search crawlers not to index or follow
+  assert.match(
+    postLayout,
+    /noindex,\s*nofollow/i,
+    "post.njk must define 'noindex, nofollow' robots meta tag when hidden"
+  );
+  assert.match(
+    postLayout,
+    /{%\s*if\s+hidden\b/i,
+    "post.njk must conditionally check if post is hidden"
+  );
+});
+
+
+test("Hidden Posts: Obsidian normalization preserves hidden frontmatter property", () => {
+  const obsidianNote = `---
+title: "Confidential System Blueprint"
+created: 2026-09-23
+tags: ["#architecture", "#secret"]
+hidden: true
+---
+
+# Blueprint
+Details for authorized eyes only.
+`;
+
+  const normalized = normalizeObsidianMarkdown(obsidianNote);
+  assert.match(normalized, /hidden:\s*true/, "Normalized markdown must preserve 'hidden: true'");
+  assert.match(normalized, /title:\s*"Confidential System Blueprint"/, "Preserves title");
+  assert.match(normalized, /date:\s*2026-09-23/, "Bridges created to date");
+  assert.match(normalized, /layout:\s*layouts\/post\.njk/, "Adds post layout");
+});
+
+test("Hidden Posts: End-to-end static compilation and accessibility via direct link", async () => {
+  const tmpDir = fs.mkdtempSync(path.join(process.cwd(), "test-tmp-site-"));
+  const tmpPosts = fs.mkdtempSync(path.join(process.cwd(), "test-tmp-posts-"));
+
+  try {
+    // 1. Create a public post and a hidden post
+    const publicPostContent = `---
+title: "Public Announcement"
+date: 2026-09-20
+layout: layouts/post.njk
+tags: ["news"]
+excerpt: "This is a public announcement for everyone to read."
+---
+Public content visible to everyone.`;
+
+    const hiddenPostContent = `---
+title: "Private Unlisted Memo"
+date: 2026-09-22
+layout: layouts/post.njk
+tags: ["confidential"]
+excerpt: "This is an unlisted memo meant for direct link access only."
+hidden: true
+---
+Secret memo content available by link only.`;
+
+    fs.writeFileSync(path.join(tmpPosts, "2026-09-20-public-post.md"), publicPostContent, "utf-8");
+    fs.writeFileSync(path.join(tmpPosts, "2026-09-22-secret-memo.md"), hiddenPostContent, "utf-8");
+
+    // 2. Set up server with custom directories
+    process.env.API_SECRET = "test-secret";
+    const server = createServer(tmpDir, tmpPosts);
+    await new Promise((resolve) => server.listen(0, "127.0.0.1", resolve));
+    const port = server.address().port;
+
+    try {
+      // Simulate static files created by build
+      fs.mkdirSync(path.join(tmpDir, "posts/2026-09-22-secret-memo"), { recursive: true });
+      fs.mkdirSync(path.join(tmpDir, "posts/2026-09-20-public-post"), { recursive: true });
+
+      const secretHtml = `<!DOCTYPE html><html><head><title>Private Unlisted Memo</title><meta name="robots" content="noindex, nofollow"></head><body>Secret memo content available by link only.</body></html>`;
+      const publicHtml = `<!DOCTYPE html><html><head><title>Public Announcement</title></head><body>Public content visible to everyone.</body></html>`;
+      const indexHtml = `<!DOCTYPE html><html><body><a href="/posts/2026-09-20-public-post/">Public Announcement</a></body></html>`;
+
+      fs.writeFileSync(path.join(tmpDir, "posts/2026-09-22-secret-memo/index.html"), secretHtml);
+      fs.writeFileSync(path.join(tmpDir, "posts/2026-09-20-public-post/index.html"), publicHtml);
+      fs.writeFileSync(path.join(tmpDir, "index.html"), indexHtml);
+
+      // Verify direct access to hidden post succeeds (HTTP 200 OK)
+      const resSecret = await fetch(`http://127.0.0.1:${port}/posts/2026-09-22-secret-memo/`);
+      assert.strictEqual(resSecret.status, 200, "Direct link to hidden post must return 200 OK");
+      const secretBody = await resSecret.text();
+      assert.match(secretBody, /Secret memo content available by link only/, "Hidden post body is accessible");
+      assert.match(secretBody, /noindex,\s*nofollow/, "Hidden post includes noindex meta tag");
+
+      // Verify public index does NOT contain link or title to hidden post
+      const resIndex = await fetch(`http://127.0.0.1:${port}/`);
+      assert.strictEqual(resIndex.status, 200);
+      const indexBody = await resIndex.text();
+      assert.match(indexBody, /Public Announcement/, "Public post is listed on index");
+      assert.doesNotMatch(indexBody, /Private Unlisted Memo/, "Hidden post MUST NOT appear on index");
+      assert.doesNotMatch(indexBody, /secret-memo/, "Hidden post link MUST NOT appear on index");
+    } finally {
+      await new Promise((resolve) => server.close(resolve));
+    }
+  } finally {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+    fs.rmSync(tmpPosts, { recursive: true, force: true });
+  }
+});
+
+test("Hidden Posts: Obsidian API ingestion correctly writes hidden frontmatter", async () => {
+  const tmpDir = fs.mkdtempSync(path.join(process.cwd(), "test-tmp-site-"));
+  const tmpPosts = fs.mkdtempSync(path.join(process.cwd(), "test-tmp-posts-"));
+  process.env.API_SECRET = "test-secret";
+
+  const server = createServer(tmpDir, tmpPosts);
+  await new Promise((resolve) => server.listen(0, "127.0.0.1", resolve));
+  const port = server.address().port;
+
+  try {
+    const res = await fetch(`http://127.0.0.1:${port}/api/posts`, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+        Authorization: "Bearer test-secret"
+      },
+      body: JSON.stringify({
+        slug: "unlisted-post",
+        content: `---
+title: "Direct Share Only"
+created: 2026-09-23
+hidden: true
+tags: ["#private"]
+---
+Secret note content.`
+      })
+    });
+
+    assert.strictEqual(res.status, 200);
+    const json = await res.json();
+    assert.strictEqual(json.status, "published");
+    assert.strictEqual(json.path, "/posts/unlisted-post/");
+
+    const writtenFile = path.join(tmpPosts, "unlisted-post.md");
+    assert.ok(fs.existsSync(writtenFile), "Post file must exist");
+    const writtenContent = fs.readFileSync(writtenFile, "utf-8");
+    assert.match(writtenContent, /hidden:\s*true/);
+    assert.match(writtenContent, /layout:\s*layouts\/post\.njk/);
+  } finally {
+    await new Promise((resolve) => server.close(resolve));
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+    fs.rmSync(tmpPosts, { recursive: true, force: true });
+  }
+});
+
diff --git a/test/standards-verification.test.js b/test/standards-verification.test.js
new file mode 100644
index 0000000..aa52166
--- /dev/null
+++ b/test/standards-verification.test.js
@@ -0,0 +1,92 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import path from "node:path";
+
+const skillDir = path.resolve(".agents/skills/standards-verification");
+const skillPath = path.join(skillDir, "SKILL.md");
+const standardsDocPath = path.resolve(".agents/standards.md");
+const skillStandardsRefPath = path.join(skillDir, "references/standards.md");
+
+test("Standards Verification Skill: Directory, SKILL.md, and standards document exist", () => {
+  assert.ok(fs.existsSync(skillDir), ".agents/skills/standards-verification directory must exist");
+  assert.ok(fs.existsSync(skillPath), "SKILL.md must exist in standards-verification skill");
+  assert.ok(fs.existsSync(standardsDocPath), "Dedicated standards document .agents/standards.md must exist");
+  assert.ok(fs.existsSync(skillStandardsRefPath), "Skill references/standards.md must exist");
+});
+
+test("Standards Verification Skill: SKILL.md contains correct metadata and execution directives", () => {
+  const content = fs.readFileSync(skillPath, "utf-8");
+
+  // 1. YAML frontmatter name and description
+  assert.match(content, /^---\s*\nname:\s*standards-verification/m, "Must declare name: standards-verification");
+  assert.match(content, /description:\s*>-?[\s\S]*?---/, "Must define description in frontmatter");
+
+  // 2. Invocation conditions: called sparingly, major feature, user request, or debugging
+  assert.match(content, /sparingly/i, "Must specify calling sparingly and only when needed");
+  assert.match(content, /major\s+function|major\s+feature/i, "Must mention use case: major function/feature implemented");
+  assert.match(content, /user(?:\s+\w+)?\s+asks/i, "Must mention use case: user explicitly requests verification");
+  assert.match(content, /debug(?:ging)?/i, "Must mention use case: debugging code issues");
+
+  // 3. Targeted inspection via git status / git diff (not whole codebase unless necessary)
+  assert.match(content, /git\s+status/i, "Must specify using git status to identify changes");
+  assert.match(content, /git\s+diff/i, "Must specify using git diff to inspect targeted changes");
+  assert.match(content, /not\s+(?:the\s+)?whole\s+codebase/i, "Must specify NOT inspecting whole codebase unless necessary");
+
+  // 4. Debugging guidance: explain why standards violations cause errors
+  assert.match(content, /(?:suggest|explain)[*\s`_]+why/i, "Must instruct suggesting why standards issues cause errors");
+
+
+  // 5. External standards document reference
+  assert.match(content, /standards\.md/i, "Must refer to standards.md rather than embedding standards directly");
+});
+
+test("Standards Document: Comprehensive specifications across all architectural layers", () => {
+  const content = fs.readFileSync(standardsDocPath, "utf-8");
+
+  // 1. Design & CSS Anti-Patterns
+  assert.match(content, /backdrop-filter/i, "Must document prohibition on backdrop-filter");
+  assert.match(content, /box-shadow/i, "Must document prohibition on box-shadow");
+  assert.match(content, /gradient/i, "Must document prohibition on gradients");
+  assert.match(content, /border-radius/i, "Must document border-radius constraints (0px to 4px)");
+  assert.match(content, /instant/i, "Must document instant binary transitions");
+
+  // 2. Templating & Eleventy
+  assert.match(content, /isPostPublic/i, "Must document isPostPublic collection filtering");
+  assert.match(content, /hidden/i, "Must document hidden post behavior and noindex meta tag");
+
+  // 3. Frontmatter & Content Contract
+  assert.match(content, /title/i, "Must document title requirement");
+  assert.match(content, /date|created/i, "Must document date requirement");
+  assert.match(content, /tags/i, "Must document tags requirement");
+  assert.match(content, /excerpt/i, "Must document excerpt requirement");
+
+  // 4. Server & Security Invariants
+  assert.match(content, /path\s+traversal/i, "Must document path traversal defense");
+  assert.match(content, /healthz/i, "Must document healthcheck endpoint");
+  assert.match(content, /X-Content-Type-Options/i, "Must document security headers");
+
+  // 5. Strict TDD & Verification Invariants
+  assert.match(content, /before\s+(?:writing\s+or\s+)?modifying/i, "Must mandate tests before modifying functional code");
+  assert.match(content, /adversarial/i, "Must mandate adversarial testing");
+  assert.match(content, /pass\s+before\s+presenting/i, "Must mandate tests pass before presenting final output");
+});
+
+test("Standards Verification Skill: Adversarial checks against full-codebase scanning defaults", () => {
+  const content = fs.readFileSync(skillPath, "utf-8");
+
+  // Adversarial: ensure no instruction tells the agent to indiscriminately scan everything by default
+  assert.doesNotMatch(
+    content,
+    /always\s+scan\s+(?:all|the\s+entire|the\s+whole)\s+codebase/i,
+    "Must not default to scanning the whole codebase"
+  );
+});
+
+test("Standards Verification Skill: Helper script verify.js exists and executes safely", () => {
+  const scriptPath = path.join(skillDir, "scripts/verify.js");
+  assert.ok(fs.existsSync(scriptPath), "scripts/verify.js must exist");
+  const content = fs.readFileSync(scriptPath, "utf-8");
+  assert.match(content, /git\s+status/i, "Script must inspect git status");
+});
+