[codex] Refactor skills into focused references (#135)

* docs: add runtime-neutral User Input Tools convention across skills

Introduce docs/user-input-tools.md as the author-side canonical source
and inline the tool-selection rule into every SKILL.md that prompts
the user. Also add Skill Self-Containment and User Input Tools sections
to CLAUDE.md and the copy-verbatim template to docs/creating-skills.md,
so skills stay portable across Claude Code, Codex, Hermes, and other
runtimes.

* feat: runtime-neutral image generation convention across skills

- Introduce inline `## Image Generation Tools` rule in every rendering SKILL.md so skills delegate backend choice instead of hard-coding one; author-side canonical copy lives in docs/image-generation-tools.md.
- Add `## Reference Images` support (`--ref`, frontmatter `references:` with direct/style/palette usage) to all seven image-rendering skills.
- Move build-batch.ts (with ref propagation into batch JSON) from baoyu-article-illustrator to baoyu-imagine so non-backend skills don't own backend-specific scripts; update baoyu-image-gen stub in sync and relax the CLAUDE.md deprecation note accordingly.

* refactor: slim heavy SKILL.md files and move detail to references/

Trim the four largest active skills and move presets, option tables, and
confirmation scripts into per-skill references/ so SKILL.md stays focused
on the decision flow.

- baoyu-slide-deck: 761→258, + styles-gallery.md, confirmation.md
- baoyu-image-cards: 657→280, + gallery.md, confirmation.md
- baoyu-post-to-wechat: 518→267, + multi-account.md, api-setup.md
- baoyu-imagine: 500→230, + providers/, usage-examples.md

Also un-deprecate baoyu-image-gen (drop stub warning) so it stays functional
alongside baoyu-imagine, and update CLAUDE.md to reflect that both
superseded skills are kept in sync rather than stubbed.

* refactor: slim four medium SKILL.md files into references/

Continue the P2 pattern on the next tier of skills — move option catalogs,
per-provider/adapter detail, and repeated EXTEND.md path boilerplate into
their own references so SKILL.md stays focused on the decision flow.

- baoyu-comic: 380→297 (art/tone/preset tables → auto-selection.md;
  Step 7 expanded detail → workflow.md)
- baoyu-infographic: 312→207 (layouts/styles/combinations/keywords →
  gallery.md; ASCII box tables → markdown tables)
- baoyu-format-markdown: 376→296 (title + summary generation →
  title-summary.md; ASCII box tables → markdown tables)
- baoyu-url-to-markdown: 334→169 (quality gate + recovery →
  quality-gate.md; adapters + media download → adapters.md)

* chore: sync deprecated skills with their replacements

Per project policy, baoyu-xhs-images and baoyu-image-gen are kept
functional alongside the active skills they were superseded by. Sync
their SKILL.md bodies and references/ to the slimmed baoyu-image-cards
and baoyu-imagine versions respectively, so cross-cutting fixes stay
consistent. Only the frontmatter (name, description, version, homepage)
differs — content is identical.

- baoyu-xhs-images: 657→281 (synced with baoyu-image-cards + new
  confirmation.md, gallery.md)
- baoyu-image-gen: 408→231 (synced with baoyu-imagine + new
  providers/, usage-examples.md)

* refactor: collapse EXTEND.md boilerplate into priority tables

Replace the dual bash/powershell existence-check blocks and ASCII box
art with a single markdown priority table across nine SKILL.md files.
The runtime-neutral phrasing removes shell-specific snippets without
losing the priority semantics.

* fix: address refactor-skills branch review findings

- image-gen: restore EXTEND.md paths to baoyu-image-gen (were pointing at
  baoyu-imagine) and mark descriptions of both deprecated skills as
  [Deprecated].
- xhs-images: sync neon/warm palettes with image-cards to add the
  "do not render color names/hex as visible text" safety sentence.
- infographic: restore Layout Gallery (21), Style Gallery (21),
  Recommended Combinations, and Keyword Shortcuts inline (previous
  refactor split them out but SKILL.md still depended on them), and add
  the missing references/config/first-time-setup.md + preferences-schema.md.
- image-cards / xhs-images / slide-deck / format-markdown: restore the
  sections that got over-slimmed into references/ (galleries, presets,
  dimensions, auto-selection, style x layout matrix, title/summary flow)
  and drop the now-empty shell files.
- docs/image-generation-tools.md: note that backend skills themselves
  (baoyu-imagine, baoyu-image-gen, baoyu-danger-gemini-web) are exempt
  from the ## Image Generation Tools section requirement.

* feat(image-gen): sync Z.AI GLM-Image provider from baoyu-imagine

Add Z.AI as a full provider in the deprecated baoyu-image-gen skill so
it stays in sync with baoyu-imagine's provider list.

- new scripts/providers/zai.ts + zai.test.ts (verbatim port; test
  factory trimmed to match image-gen's CliArgs shape).
- types.ts: "zai" added to Provider union and default_model.
- main.ts: rate-limit defaults, provider help text, env var help,
  --provider validation, loadProviderModule, detectProvider
  auto-detect chain, getModelForProvider, YAML parser allow-lists.
- references/config: Q2e Z.AI model question + zai slot in the
  preferences schema and batch.provider_limits.

Scope is intentionally limited to the Z.AI chain; unrelated drift
between image-gen and imagine (OpenAI image-API dialect,
aspectRatioSource, imageSizeSource) is left alone.

* docs: align inline-convention wording and note backend-skill exemption

- docs/user-input-tools.md: fix stale "links here" wording so it
  matches the inline convention already enforced everywhere else.
- CLAUDE.md §Image Generation Tools: inline the backend-skill
  exemption so readers don't need to cross-reference
  docs/image-generation-tools.md.

skills/baoyu-post-to-x/SKILL.md

@@ -39,40 +39,17 @@ Posts text, images, videos, and long-form articles to X via real Chrome browser
 
 ## Preferences (EXTEND.md)
 
-Check EXTEND.md existence (priority order):
+Check EXTEND.md in priority order — the first one found wins:
 
-```bash
-# macOS, Linux, WSL, Git Bash
-test -f .baoyu-skills/baoyu-post-to-x/EXTEND.md && echo "project"
-test -f "${XDG_CONFIG_HOME:-$HOME/.config}/baoyu-skills/baoyu-post-to-x/EXTEND.md" && echo "xdg"
-test -f "$HOME/.baoyu-skills/baoyu-post-to-x/EXTEND.md" && echo "user"
-```
+| Priority | Path | Scope |
+|----------|------|-------|
+| 1 | `.baoyu-skills/baoyu-post-to-x/EXTEND.md` | Project |
+| 2 | `${XDG_CONFIG_HOME:-$HOME/.config}/baoyu-skills/baoyu-post-to-x/EXTEND.md` | XDG |
+| 3 | `$HOME/.baoyu-skills/baoyu-post-to-x/EXTEND.md` | User home |
 
-```powershell
-# PowerShell (Windows)
-if (Test-Path .baoyu-skills/baoyu-post-to-x/EXTEND.md) { "project" }
-$xdg = if ($env:XDG_CONFIG_HOME) { $env:XDG_CONFIG_HOME } else { "$HOME/.config" }
-if (Test-Path "$xdg/baoyu-skills/baoyu-post-to-x/EXTEND.md") { "xdg" }
-if (Test-Path "$HOME/.baoyu-skills/baoyu-post-to-x/EXTEND.md") { "user" }
-```
+If none found, use defaults.
 
-┌──────────────────────────────────────────────────┬───────────────────┐
-│                       Path                       │     Location      │
-├──────────────────────────────────────────────────┼───────────────────┤
-│ .baoyu-skills/baoyu-post-to-x/EXTEND.md          │ Project directory │
-├──────────────────────────────────────────────────┼───────────────────┤
-│ $HOME/.baoyu-skills/baoyu-post-to-x/EXTEND.md    │ User home         │
-└──────────────────────────────────────────────────┴───────────────────┘
-
-┌───────────┬───────────────────────────────────────────────────────────────────────────┐
-│  Result   │                                  Action                                   │
-├───────────┼───────────────────────────────────────────────────────────────────────────┤
-│ Found     │ Read, parse, apply settings                                               │
-├───────────┼───────────────────────────────────────────────────────────────────────────┤
-│ Not found │ Use defaults                                                              │
-└───────────┴───────────────────────────────────────────────────────────────────────────┘
-
-**EXTEND.md Supports**: Default Chrome profile
+**EXTEND.md supports**: Default Chrome profile
 
 ## Prerequisites