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>

public/css/workflow.css

@@ -181,6 +181,24 @@
   font-weight: 300;
 }
 
+/* Sub-commands: stack the /impeccable namespace as a smaller label above the
+   command name so the command name stays at full display size and never
+   clips (e.g., "overdrive" is long). */
+.spread-command-name .spread-namespace {
+  display: block;
+  font-family: var(--font-body);
+  font-size: 0.875rem;
+  font-weight: 500;
+  color: var(--color-ash);
+  letter-spacing: 0.04em;
+  margin-bottom: 0.4em;
+}
+
+.spread-command-name .spread-namespace .spread-slash {
+  color: var(--spread-accent);
+  font-weight: 400;
+}
+
 .spread-command-name .beta-badge {
   font-family: var(--font-body);
   font-size: 0.55rem;