feat: Added /about page with three content sections (what, how, who) an…

- "frontend/src/pages/About.tsx"
- "frontend/src/App.tsx"
- "frontend/src/components/AppFooter.tsx"
- "frontend/src/App.css"

GSD-Task: S02/T01

.gsd/milestones/M009/M009-ROADMAP.md

@@ -6,6 +6,6 @@ The homepage is Chrysopedia's front door. Right now it's a search box — functi
 ## Slice Overview
 | ID | Slice | Risk | Depends | Done | After this |
 |----|-------|------|---------|------|------------|
-| S01 | Homepage Hero & Value Proposition | medium | — | ⬜ | Homepage shows tagline, value description, how-it-works steps, Start Exploring CTA, and popular topic quick-links above the fold |
+| S01 | Homepage Hero & Value Proposition | medium | — | ✅ | Homepage shows tagline, value description, how-it-works steps, Start Exploring CTA, and popular topic quick-links above the fold |
 | S02 | About Page | low | — | ⬜ | About page at /about explains what Chrysopedia is, how content is extracted, and who maintains it. Link visible in footer. |
 | S03 | Featured Content & Content Teasers | low | S01 | ⬜ | Homepage shows a featured technique spotlight and Recently Added section with enriched cards |

.gsd/milestones/M009/slices/S01/S01-SUMMARY.md

@@ -0,0 +1,81 @@
+---
+id: S01
+parent: M009
+milestone: M009
+provides:
+  - Homepage hero section with tagline, value prop, how-it-works, CTA — S03 builds on this layout for featured content
+requires:
+  []
+affects:
+  - S03
+key_files:
+  - frontend/src/pages/Home.tsx
+  - frontend/src/App.css
+key_decisions:
+  - Used cyan accent numbered circles for how-it-works steps to match existing design language
+  - Used uppercase secondary-text heading for Popular Topics to differentiate from primary content hierarchy
+  - Popular topics pills link to /search?q={topic}&scope=topics rather than a dedicated topic detail page
+patterns_established:
+  - Homepage content sections use BEM naming under .home- prefix (home-hero__title, home-how-it-works__step, home-popular-topics)
+  - Optional data-driven sections (popular topics) silently hide on API error — no error UI for non-critical homepage enrichment
+observability_surfaces:
+  - none
+drill_down_paths:
+  - .gsd/milestones/M009/slices/S01/tasks/T01-SUMMARY.md
+  - .gsd/milestones/M009/slices/S01/tasks/T02-SUMMARY.md
+duration: ""
+verification_result: passed
+completed_at: 2026-03-31T05:38:05.139Z
+blocker_discovered: false
+---
+
+# S01: Homepage Hero & Value Proposition
+
+**Homepage now shows tagline, value proposition, 3-step how-it-works grid, Start Exploring CTA, and popular topic quick-links — all above the fold.**
+
+## What Happened
+
+The homepage previously had an empty h1 and only a subtitle with search bar. Two tasks transformed it into a proper landing experience:
+
+**T01** added the hero tagline "Production Knowledge, Distilled", a value proposition paragraph explaining what Chrysopedia does, a 3-column how-it-works grid (Creators Share Techniques → AI Extracts Key Moments → You Find Answers Fast) with cyan accent numbered circles, and a prominent "Start Exploring" CTA button linking to /topics. All styling uses existing CSS custom properties. Responsive stacking at 640px.
+
+**T02** added a Popular Topics section that fetches from the existing topics API, flattens all sub_topics across categories, sorts by technique_count descending, takes the top 8, and renders them as clickable pill links navigating to /search?q={topic}&scope=topics. Section is hidden when no data or API error — graceful degradation. CSS uses the existing pill token system with bordered hover state.
+
+Both tasks touched only Home.tsx and App.css. No new dependencies, no API changes, no backend work required.
+
+## Verification
+
+Frontend build passes with zero errors (46 modules transformed, 52KB CSS, 224KB JS). Verified all planned elements present in source: h1 tagline, value-prop paragraph, how-it-works grid with 3 steps, CTA link to /topics, popularTopics state/fetch/render, pill links with search scope. CSS classes confirmed present for all new components including responsive rules.
+
+## Requirements Advanced
+
+None.
+
+## Requirements Validated
+
+None.
+
+## New Requirements Surfaced
+
+None.
+
+## Requirements Invalidated or Re-scoped
+
+None.
+
+## Deviations
+
+T02 removed an unused TopicCategory type import that caused TS6133 — minor cleanup, no functional impact.
+
+## Known Limitations
+
+Popular topics section fetches the full topics list and filters client-side. Fine for current dataset size but would benefit from a dedicated API endpoint if topic count grows significantly.
+
+## Follow-ups
+
+None.
+
+## Files Created/Modified
+
+- `frontend/src/pages/Home.tsx` — Added hero tagline, value proposition, how-it-works grid, CTA button, and popular topics pill section with API fetch
+- `frontend/src/App.css` — Added styles for value-prop, how-it-works grid, CTA button, popular topics pills, and responsive breakpoints

.gsd/milestones/M009/slices/S01/S01-UAT.md

@@ -0,0 +1,45 @@
+# S01: Homepage Hero & Value Proposition — UAT
+
+**Milestone:** M009
+**Written:** 2026-03-31T05:38:05.139Z
+
+## UAT: Homepage Hero & Value Proposition
+
+### Preconditions
+- Chrysopedia stack running (web UI accessible at configured URL)
+- At least one topic with sub-topics exists in the database (for popular topics to render)
+
+### Test 1: Hero Content Visible
+1. Navigate to the homepage (/)
+2. **Expected:** Page shows heading "Production Knowledge, Distilled"
+3. **Expected:** Below the heading, a paragraph explains what Chrysopedia does — mentions extracting techniques from creator tutorials
+4. **Expected:** Search bar remains visible and prominent
+
+### Test 2: How-It-Works Grid
+1. On the homepage, locate the how-it-works section
+2. **Expected:** Three steps displayed in a row (desktop): (1) Creators Share Techniques, (2) AI Extracts Key Moments, (3) You Find Answers Fast
+3. **Expected:** Each step has a numbered circle with cyan accent color and a short description
+4. Resize browser to <640px width
+5. **Expected:** Steps stack vertically
+
+### Test 3: Start Exploring CTA
+1. On the homepage, locate the "Start Exploring" button
+2. Click the button
+3. **Expected:** Navigates to /topics page
+
+### Test 4: Popular Topics Pills
+1. Navigate back to homepage (/)
+2. **Expected:** A "Popular Topics" section appears with up to 8 pill/chip links
+3. **Expected:** Pills are ordered by technique count (most popular first)
+4. Click any topic pill
+5. **Expected:** Navigates to /search?q={topic_name}&scope=topics with relevant results
+
+### Test 5: Popular Topics — Empty State
+1. If no topics exist in the database (or API is down), navigate to homepage
+2. **Expected:** Popular Topics section is completely hidden — no heading, no empty container, no error message
+
+### Test 6: Visual Hierarchy
+1. On desktop (>768px), load the homepage
+2. **Expected:** Hero title and search bar are visible without scrolling
+3. **Expected:** How-it-works section and CTA are below but reachable with minimal scroll
+4. **Expected:** Popular topics pills visually complement but don't compete with the search bar

.gsd/milestones/M009/slices/S01/tasks/T02-VERIFY.json

@@ -0,0 +1,16 @@
+{
+  "schemaVersion": 1,
+  "taskId": "T02",
+  "unitId": "M009/S01/T02",
+  "timestamp": 1774935430315,
+  "passed": true,
+  "discoverySource": "task-plan",
+  "checks": [
+    {
+      "command": "cd frontend",
+      "exitCode": 0,
+      "durationMs": 6,
+      "verdict": "pass"
+    }
+  ]
+}

.gsd/milestones/M009/slices/S02/S02-PLAN.md

@@ -1,6 +1,10 @@
 # S02: About Page
 
-**Goal:** Project credibility — users can learn who made this and why
+**Goal:** About page at /about explains what Chrysopedia is, how content is extracted, and who maintains it. Footer link navigates to it.
 **Demo:** After this: About page at /about explains what Chrysopedia is, how content is extracted, and who maintains it. Link visible in footer.
 
 ## Tasks
+- [x] **T01: Added /about page with three content sections (what, how, who) and an About link in the footer** — Create the About.tsx page component with three content sections (what Chrysopedia is, how content is extracted, who maintains it), add a /about route in App.tsx, add an About link in AppFooter.tsx, and add .about-* styles in App.css following existing BEM and CSS custom property patterns.
+  - Estimate: 30m
+  - Files: frontend/src/pages/About.tsx, frontend/src/App.tsx, frontend/src/components/AppFooter.tsx, frontend/src/App.css
+  - Verify: cd frontend && npx tsc --noEmit && npm run build

.gsd/milestones/M009/slices/S02/S02-RESEARCH.md

@@ -0,0 +1,40 @@
+# S02 Research — About Page
+
+## Summary
+
+Static informational page at `/about` explaining what Chrysopedia is, how content is extracted, and who maintains it. No backend work. Three changes: new page component, new route in App.tsx, footer link.
+
+## Recommendation
+
+Follow existing page patterns exactly. This is the simplest possible slice — a single static React component with CSS, wired into the router and linked from the footer.
+
+## Implementation Landscape
+
+### Files to Create
+- `frontend/src/pages/About.tsx` — static page component
+
+### Files to Modify
+- `frontend/src/App.tsx` — add `<Route path="/about" element={<About />} />`
+- `frontend/src/components/AppFooter.tsx` — add "About" link (use react-router-dom `Link`, not `<a>`)
+- `frontend/src/App.css` — add `.about-*` styles
+
+### Existing Patterns to Follow
+- **Page structure:** Wrap in a container div with page-specific class (e.g. `<div className="about">`). See Home.tsx for hero/section pattern.
+- **Routing:** App.tsx uses `react-router-dom` `Routes`/`Route`. Import lazy or direct, add `<Route path="/about" element={<About />} />`.
+- **Footer:** `AppFooter.tsx` currently has version info, build date, commit hash, and GitHub link. Add an "About" `<Link to="/about">` before or after the GitHub link, with the same `app-footer__sep` separator pattern.
+- **CSS variables:** All colors use `var(--color-*)` custom properties defined in `:root` in App.css (77 tokens per D017). Use `--color-text-primary`, `--color-text-secondary`, `--color-text-muted`, `--color-surface-secondary`, `--color-accent`, `--color-border` etc.
+- **BEM-ish naming:** Classes follow `block__element` pattern (e.g. `home-hero__title`, `nav-card__desc`).
+
+### Content for the About Page
+The roadmap specifies three content areas:
+1. **What Chrysopedia is** — a knowledge base of music production techniques extracted from creator tutorials
+2. **How content is extracted** — mirrors the Home "how it works" 3-step flow (creators share → AI extracts → you search), but with more detail about the pipeline (transcription, LLM extraction, review, synthesis)
+3. **Who maintains it** — link to xpltdco GitHub org, note it's an XPLTD project
+
+### Verification
+- `cd frontend && npx tsc --noEmit` — zero TypeScript errors
+- `cd frontend && npm run build` — production build succeeds
+- Visual: navigate to `/about` in browser, confirm content renders, confirm footer link works
+
+### Natural Task Decomposition
+This is a single-task slice. Creating the component, adding the route, adding the footer link, and adding CSS are tightly coupled and trivial — splitting further adds overhead without value. One task: "Implement About page with route and footer link."

.gsd/milestones/M009/slices/S02/tasks/T01-PLAN.md

@@ -0,0 +1,27 @@
+---
+estimated_steps: 1
+estimated_files: 4
+skills_used: []
+---
+
+# T01: Implement About page with route and footer link
+
+Create the About.tsx page component with three content sections (what Chrysopedia is, how content is extracted, who maintains it), add a /about route in App.tsx, add an About link in AppFooter.tsx, and add .about-* styles in App.css following existing BEM and CSS custom property patterns.
+
+## Inputs
+
+- ``frontend/src/App.tsx` — existing routing structure to add /about route`
+- ``frontend/src/components/AppFooter.tsx` — existing footer to add About link`
+- ``frontend/src/App.css` — existing CSS custom properties and BEM patterns`
+- ``frontend/src/pages/Home.tsx` — reference for page component structure and hero/section patterns`
+
+## Expected Output
+
+- ``frontend/src/pages/About.tsx` — new About page component with three content sections`
+- ``frontend/src/App.tsx` — modified with /about route and About import`
+- ``frontend/src/components/AppFooter.tsx` — modified with About link using react-router-dom Link`
+- ``frontend/src/App.css` — modified with .about-* styles`
+
+## Verification
+
+cd frontend && npx tsc --noEmit && npm run build

.gsd/milestones/M009/slices/S02/tasks/T01-SUMMARY.md

@@ -0,0 +1,81 @@
+---
+id: T01
+parent: S02
+milestone: M009
+provides: []
+requires: []
+affects: []
+key_files: ["frontend/src/pages/About.tsx", "frontend/src/App.tsx", "frontend/src/components/AppFooter.tsx", "frontend/src/App.css"]
+key_decisions: ["Used CSS counter-based numbered pipeline steps rather than manual numbering for the extraction pipeline section"]
+patterns_established: []
+drill_down_paths: []
+observability_surfaces: []
+duration: ""
+verification_result: "npx tsc --noEmit passed with zero errors. npm run build produced the production bundle successfully (47 modules, no warnings)."
+completed_at: 2026-03-31T05:41:48.153Z
+blocker_discovered: false
+---
+
+# T01: Added /about page with three content sections (what, how, who) and an About link in the footer
+
+> Added /about page with three content sections (what, how, who) and an About link in the footer
+
+## What Happened
+---
+id: T01
+parent: S02
+milestone: M009
+key_files:
+  - frontend/src/pages/About.tsx
+  - frontend/src/App.tsx
+  - frontend/src/components/AppFooter.tsx
+  - frontend/src/App.css
+key_decisions:
+  - Used CSS counter-based numbered pipeline steps rather than manual numbering for the extraction pipeline section
+duration: ""
+verification_result: passed
+completed_at: 2026-03-31T05:41:48.153Z
+blocker_discovered: false
+---
+
+# T01: Added /about page with three content sections (what, how, who) and an About link in the footer
+
+**Added /about page with three content sections (what, how, who) and an About link in the footer**
+
+## What Happened
+
+Created About.tsx with three sections: what Chrysopedia is, a five-step pipeline breakdown explaining how content is extracted, and a maintainer section linking to the xpltd GitHub org and repo. Added the /about route in App.tsx between admin routes and the fallback. Added an About link as the last item in AppFooter.tsx using react-router-dom Link. Added .about-* styles in App.css following existing BEM and custom property patterns, including a responsive breakpoint for the hero title.
+
+## Verification
+
+npx tsc --noEmit passed with zero errors. npm run build produced the production bundle successfully (47 modules, no warnings).
+
+## Verification Evidence
+
+| # | Command | Exit Code | Verdict | Duration |
+|---|---------|-----------|---------|----------|
+| 1 | `cd frontend && npx tsc --noEmit` | 0 | ✅ pass | 2200ms |
+| 2 | `cd frontend && npm run build` | 0 | ✅ pass | 1200ms |
+
+
+## Deviations
+
+None.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `frontend/src/pages/About.tsx`
+- `frontend/src/App.tsx`
+- `frontend/src/components/AppFooter.tsx`
+- `frontend/src/App.css`
+
+
+## Deviations
+None.
+
+## Known Issues
+None.

frontend/src/App.css

@@ -3354,3 +3354,126 @@ a.app-footer__repo:hover {
   gap: 0.3rem;
   text-decoration: none;
 }
+
+/* ── About page ───────────────────────────────────────────────────────────── */
+
+.about {
+  max-width: 44rem;
+  margin: 0 auto;
+  padding: 2rem 1.5rem 3rem;
+}
+
+.about-hero {
+  text-align: center;
+  margin-bottom: 2.5rem;
+}
+
+.about-hero__title {
+  font-size: 2rem;
+  font-weight: 700;
+  color: var(--color-text-primary);
+  margin: 0 0 0.5rem;
+}
+
+.about-hero__subtitle {
+  font-size: 1.05rem;
+  color: var(--color-text-secondary);
+  margin: 0;
+}
+
+.about-section {
+  margin-bottom: 2rem;
+}
+
+.about-section__heading {
+  font-size: 1.25rem;
+  font-weight: 600;
+  color: var(--color-text-primary);
+  margin: 0 0 0.75rem;
+}
+
+.about-section__text {
+  color: var(--color-text-secondary);
+  line-height: 1.7;
+  margin: 0 0 0.75rem;
+}
+
+.about-pipeline {
+  list-style: none;
+  counter-reset: pipeline;
+  padding: 0;
+  margin: 1rem 0;
+  display: flex;
+  flex-direction: column;
+  gap: 0.75rem;
+}
+
+.about-pipeline__step {
+  counter-increment: pipeline;
+  display: flex;
+  align-items: baseline;
+  gap: 0.75rem;
+  color: var(--color-text-secondary);
+  line-height: 1.6;
+  padding: 0.75rem 1rem;
+  background: var(--color-bg-surface);
+  border-radius: 0.5rem;
+  border: 1px solid var(--color-border);
+}
+
+.about-pipeline__step::before {
+  content: counter(pipeline);
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 1.5rem;
+  height: 1.5rem;
+  font-size: 0.75rem;
+  font-weight: 700;
+  color: var(--color-accent);
+  background: var(--color-accent-subtle);
+  border-radius: 50%;
+  flex-shrink: 0;
+}
+
+.about-pipeline__step strong {
+  color: var(--color-text-primary);
+}
+
+.about-link {
+  color: var(--color-accent);
+  text-decoration: none;
+  transition: color 0.15s;
+}
+
+.about-link:hover {
+  color: var(--color-accent-hover);
+}
+
+.about-cta {
+  text-align: center;
+  margin-top: 2.5rem;
+}
+
+.about-cta__btn {
+  display: inline-block;
+}
+
+/* Footer about link */
+
+.app-footer__about {
+  color: var(--color-text-muted);
+  text-decoration: none;
+  transition: color 0.15s;
+}
+
+a.app-footer__about:hover,
+.app-footer__about:hover {
+  color: var(--color-accent);
+}
+
+@media (max-width: 600px) {
+  .about-hero__title {
+    font-size: 1.5rem;
+  }
+}

frontend/src/App.tsx

@@ -7,6 +7,7 @@ import CreatorDetail from "./pages/CreatorDetail";
 import TopicsBrowse from "./pages/TopicsBrowse";
 import AdminReports from "./pages/AdminReports";
 import AdminPipeline from "./pages/AdminPipeline";
+import About from "./pages/About";
 import AdminDropdown from "./components/AdminDropdown";
 import AppFooter from "./components/AppFooter";
 
@@ -43,6 +44,9 @@ export default function App() {
           <Route path="/admin/reports" element={<AdminReports />} />
           <Route path="/admin/pipeline" element={<AdminPipeline />} />
 
+          {/* Info routes */}
+          <Route path="/about" element={<About />} />
+
           {/* Fallback */}
           <Route path="*" element={<Navigate to="/" replace />} />
         </Routes>

frontend/src/components/AppFooter.tsx

@@ -1,5 +1,7 @@
 const REPO_URL = "https://github.com/xpltdco/chrysopedia";
 
+import { Link } from "react-router-dom";
+
 export default function AppFooter() {
   const commitUrl =
     __GIT_COMMIT__ !== "dev"
@@ -37,6 +39,10 @@ export default function AppFooter() {
       >
         GitHub
       </a>
+      <span className="app-footer__sep">·</span>
+      <Link to="/about" className="app-footer__about">
+        About
+      </Link>
     </footer>
   );
 }

frontend/src/pages/About.tsx

@@ -0,0 +1,94 @@
+import { Link } from "react-router-dom";
+
+export default function About() {
+  return (
+    <div className="about">
+      <section className="about-hero">
+        <h1 className="about-hero__title">About Chrysopedia</h1>
+        <p className="about-hero__subtitle">
+          A structured knowledge base for music production techniques
+        </p>
+      </section>
+
+      <section className="about-section">
+        <h2 className="about-section__heading">What Is Chrysopedia?</h2>
+        <p className="about-section__text">
+          Chrysopedia turns long-form music production tutorials into a
+          searchable, structured knowledge base. Instead of scrubbing through
+          hours of video looking for the one technique you need, you can search
+          by topic, creator, or keyword and jump straight to the insight.
+        </p>
+        <p className="about-section__text">
+          The name comes from <em>chrysopoeia</em> — the art of transmutation.
+          We transmute raw video content into distilled, accessible knowledge.
+        </p>
+      </section>
+
+      <section className="about-section">
+        <h2 className="about-section__heading">How Content Is Extracted</h2>
+        <p className="about-section__text">
+          Videos are processed through a multi-stage pipeline that transcribes
+          audio, identifies key moments, classifies topics, and generates
+          structured technique pages — all using a combination of speech
+          recognition and large language models.
+        </p>
+        <ol className="about-pipeline">
+          <li className="about-pipeline__step">
+            <strong>Transcription</strong> — Audio is converted to timestamped
+            text
+          </li>
+          <li className="about-pipeline__step">
+            <strong>Key Moment Detection</strong> — The transcript is analyzed
+            to find discrete techniques and insights
+          </li>
+          <li className="about-pipeline__step">
+            <strong>Topic Classification</strong> — Each moment is tagged with
+            categories and sub-topics
+          </li>
+          <li className="about-pipeline__step">
+            <strong>Page Generation</strong> — Structured technique pages are
+            written with context, steps, and creator attribution
+          </li>
+          <li className="about-pipeline__step">
+            <strong>Indexing</strong> — Content is embedded for semantic search
+          </li>
+        </ol>
+        <p className="about-section__text">
+          Every technique page links back to its source video and creator,
+          preserving attribution throughout.
+        </p>
+      </section>
+
+      <section className="about-section">
+        <h2 className="about-section__heading">Who Maintains This</h2>
+        <p className="about-section__text">
+          Chrysopedia is built and maintained by{" "}
+          <a
+            href="https://github.com/xpltdco"
+            className="about-link"
+            target="_blank"
+            rel="noopener noreferrer"
+          >
+            xpltd
+          </a>
+          . The project is open source on{" "}
+          <a
+            href="https://github.com/xpltdco/chrysopedia"
+            className="about-link"
+            target="_blank"
+            rel="noopener noreferrer"
+          >
+            GitHub
+          </a>
+          .
+        </p>
+      </section>
+
+      <div className="about-cta">
+        <Link to="/" className="btn about-cta__btn">
+          Start Exploring
+        </Link>
+      </div>
+    </div>
+  );
+}

frontend/tsconfig.app.tsbuildinfo

@@ -1 +1 @@
-{"root":["./src/App.tsx","./src/main.tsx","./src/vite-env.d.ts","./src/api/public-client.ts","./src/components/AdminDropdown.tsx","./src/components/AppFooter.tsx","./src/components/CategoryIcons.tsx","./src/components/CopyLinkButton.tsx","./src/components/CreatorAvatar.tsx","./src/components/ReportIssueModal.tsx","./src/pages/AdminPipeline.tsx","./src/pages/AdminReports.tsx","./src/pages/CreatorDetail.tsx","./src/pages/CreatorsBrowse.tsx","./src/pages/Home.tsx","./src/pages/SearchResults.tsx","./src/pages/TechniquePage.tsx","./src/pages/TopicsBrowse.tsx"],"version":"5.6.3"}
+{"root":["./src/App.tsx","./src/main.tsx","./src/vite-env.d.ts","./src/api/public-client.ts","./src/components/AdminDropdown.tsx","./src/components/AppFooter.tsx","./src/components/CategoryIcons.tsx","./src/components/CopyLinkButton.tsx","./src/components/CreatorAvatar.tsx","./src/components/ReportIssueModal.tsx","./src/pages/About.tsx","./src/pages/AdminPipeline.tsx","./src/pages/AdminReports.tsx","./src/pages/CreatorDetail.tsx","./src/pages/CreatorsBrowse.tsx","./src/pages/Home.tsx","./src/pages/SearchResults.tsx","./src/pages/TechniquePage.tsx","./src/pages/TopicsBrowse.tsx"],"version":"5.6.3"}