Consolidate 18 skills into 1 /impeccable skill with 20 commands

Biggest change in a while. Users previously had 18 standalone skill
entries cluttering their /menu; now they have one entry (/impeccable)
that routes to 20 specialized commands via argument dispatch. The pin
mechanism (/impeccable pin audit) restores standalone shortcuts on
demand for commands users hit all the time.

## Architecture

- Single /impeccable skill with command router section in SKILL.md
- 20 commands served via reference files under source/skills/impeccable/reference/
- /impeccable pin <command> creates a lightweight redirect shim so users
  who prefer /audit, /polish, etc. can still have them
- Context gathering (teach) auto-runs on first use
- command-metadata.json is the single source of truth for command
  descriptions, argument hints, and relationships

## Site rewrite

- Docs URL: /skills renamed to /docs (with /skills permanent redirects)
- Homepage hero frames Impeccable as "one skill with 20 commands"
- "Get Started" split into 50/50 install + how-to-use with editorial
  numbered steps, /impeccable shown as the home command with three modes
- New /docs overview: home command hero card + dense category rows
  matching the old cheatsheet density, with leads-to/pairs-with/
  combines-with relationship metadata served from a shared source
- Cheatsheet merged into /docs, /cheatsheet redirects
- Magazine spread and mobile cards show /impeccable as a stacked
  namespace label above the command name at full display size
- Periodic table updated with craft/teach/extract as first-class cells
- Skill detail pages generate from reference files, with an editorial
  wrapper per command for tagline + body
- Tutorials and anti-patterns pages updated to use /impeccable <cmd>

## Build system

- Dead code removed (scripts/lib/transformers/shared.js)
- Build log wording fixed ("1 skill" not "1 skills (1 user-invocable)")
- generateApiData fallback branch removed (throws loudly if metadata
  missing instead of silently degrading)
- Commands API includes editorial tagline alongside the long description;
  UI surfaces prefer tagline for human display, description for auto-
  trigger keyword matching

## Gitignore

- Added .claude/scheduled_tasks.lock, .claude/settings.local.json to
  ignore list (local Claude Code state that should not be tracked).
- Harness skill directories (.claude/skills/, .agents/skills/, etc.)
  remain tracked by design: npx skills reads them from this repo at
  install time and they enable clean submodule use.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/lib/render-markdown.js

@@ -82,7 +82,7 @@ export function createRenderer({ knownSkillIds = new Set(), currentSkillId = nul
  *
  * - `http(s)://…` → unchanged, external
  * - `reference/foo.md` → `#reference-foo` on current skill page
- * - `/skill-id` (known) → `/skills/skill-id`
+ * - `/skill-id` (known) → `/docs/skill-id`
  * - `#anchor` → unchanged (in-page anchor)
  * - anything else → unchanged (will be caught by build warnings later)
  *
@@ -112,12 +112,12 @@ function resolveHref(href, { knownSkillIds, currentSkillId }) {
   // /skill-id mentioned in prose (e.g. "run /polish")
   const slashMatch = href.match(/^\/([a-z0-9-]+)$/i);
   if (slashMatch && knownSkillIds.has(slashMatch[1])) {
-    return { href: `/skills/${slashMatch[1]}`, external: false };
+    return { href: `/docs/${slashMatch[1]}`, external: false };
   }
 
-  // [text](other-skill) → /skills/other-skill
+  // [text](other-skill) → /docs/other-skill
   if (/^[a-z0-9-]+$/i.test(href) && knownSkillIds.has(href)) {
-    return { href: `/skills/${href}`, external: false };
+    return { href: `/docs/${href}`, external: false };
   }
 
   // Unknown — pass through. Generator can warn separately.