chore(knowledge): add course-digest skill + bundled extraction pipeline

.claude-plugin/marketplace.json

@@ -95,7 +95,7 @@
       "name": "knowledge",
       "source": "./plugins/knowledge",
       "category": "knowledge",
-      "tags": ["knowledge", "distill", "book", "pdf", "epub", "skill", "reference", "synthesis", "ingest"]
+      "tags": ["knowledge", "distill", "book", "pdf", "epub", "youtube", "video", "transcript", "course", "dometrain", "teachable", "skill", "reference", "synthesis", "ingest"]
     },
     {
       "name": "context7",

plugins/knowledge/.claude-plugin/plugin.json

@@ -1,14 +1,14 @@
 {
   "$schema": "https://json.schemastore.org/claude-code-plugin-manifest.json",
   "name": "knowledge",
-  "version": "0.4.0",
-  "description": "Ingest external knowledge into durable, synthesized artifacts. Ships a book-distillation pipeline (PDF/EPUB into concept-organized, author-attributed skill reference files) and a YouTube pipeline (watch, transcript, link harvest, and repo-applicability synthesis), plus a re-runnable setup action; a configurable library directory governs where synthesized artifacts land in the consuming repo.",
+  "version": "0.5.0",
+  "description": "Ingest external knowledge into durable, synthesized artifacts. Ships a book-distillation pipeline (PDF/EPUB into concept-organized, author-attributed skill reference files), a YouTube pipeline (watch, transcript, link harvest, and repo-applicability synthesis), and a course-digest pipeline (extract and synthesize online video courses — Dometrain, Teachable — into repo-applicable recommendations), plus a re-runnable setup action; a configurable library directory governs where synthesized artifacts land in the consuming repo.",
   "author": {
     "name": "Melodic Software",
     "email": "info@melodicsoftware.com"
   },
   "license": "MIT",
-  "keywords": ["knowledge", "distill", "book", "pdf", "epub", "youtube", "video", "transcript", "skill", "reference", "synthesis", "ingest"],
+  "keywords": ["knowledge", "distill", "book", "pdf", "epub", "youtube", "video", "transcript", "course", "dometrain", "teachable", "playwright", "skill", "reference", "synthesis", "ingest"],
   "userConfig": {
     "library_dir": {
       "type": "directory",

plugins/knowledge/CHANGELOG.md

@@ -4,6 +4,42 @@ All notable changes to the `knowledge` plugin are recorded here. The `version` i
 `.claude-plugin/plugin.json` is the delivery vehicle — a consumer receives a change
 only after that version increases.
 
+## 0.5.0
+
+### Added
+
+- **`course-digest` skill** (`/knowledge:course-digest`) — extract and synthesize
+  online video courses (Dometrain, Teachable) into repo-applicable recommendations:
+  browser-automation transcript + frame extraction, code-companion analysis, and
+  multi-modal synthesis. Actions: full pipeline, `extract`, `analyze`, `status`,
+  `resume`, `continue`.
+- Bundled `extraction/` node pipeline for the course-digest skill, with the two
+  shared libraries (`@melodic/repo-analysis`, `@melodic/video-digestion`) vendored
+  under `extraction/vendor/`. Dependencies install into `${CLAUDE_PLUGIN_DATA}` via
+  `skills/course-digest/extraction/setup-deps.mjs`, which also provisions Playwright's
+  Chromium into `${CLAUDE_PLUGIN_DATA}/ms-playwright` (idempotent; re-run after a
+  plugin update). ffmpeg and ImageMagick remain OS-level installs the skill's
+  Prerequisites section documents.
+
+### Changed
+
+- **Credential model** — course-platform login uses the user's own shell env vars
+  (`COURSE_*`/`TEACHABLE_*`, prefix driven by `platformConfig.authEnvPrefix`) with an
+  interactive manual-login fallback. Session cookies persist under
+  `${CLAUDE_PLUGIN_DATA}/auth/<platform>.auth-state.json` (out of the consumer repo),
+  keyed per platform.
+
+### Notes
+
+- The course-digest pipeline is ESM and shares the youtube skill's launcher shape
+  (`run.mjs` ESM resolve hook so bundled deps resolve from `${CLAUDE_PLUGIN_DATA}`);
+  `run.mjs` additionally pins `PLAYWRIGHT_BROWSERS_PATH` to the data directory so the
+  browser binary resolves regardless of cwd.
+- Manual login (`node:readline` + headed browser) may not function under headless
+  plugin execution; env-var + cookie-reuse carry the skill regardless.
+- `repo-analysis` and `video-digestion` are now vendored by both the youtube and
+  course-digest skills. Deduplication of the two copies is tracked separately.
+
 ## 0.4.0
 
 ### Changed
@@ -23,6 +59,14 @@ only after that version increases.
   land, restoring the stronger wording softened while the seam was unwired
   (`book-distill` remains the documented exception).
 
+## 0.3.0
+
+### Changed
+
+- **`setup` skill** — retrofit `library_dir` precedence resolution and portability
+  hardening so synthesized artifacts land at the configured library directory in the
+  consuming repo.
+
 ## 0.2.0
 
 ### Added