Distribution repo skeleton

One `npx skills add ssh://gitea/agent-skills/skills` now offers all five
skills in a grouped multi-select list. Groups come from
.claude-plugin/marketplace.json: writing-clarity, windows-tools,
image-to-data.

skills/ holds real copies rather than submodules or pointers. The installer
clones without --recurse-submodules (git.ts:241), so a submodule directory
would arrive empty, and it skips remote sources declared in a marketplace
manifest (plugin-manifest.ts:89), so only in-repo paths are resolvable.

Grouping applies only to skills listed explicitly under a plugin's skills
array with a ./-prefixed path (plugin-manifest.ts:147-151); anything not
listed falls into "Other".

think-twice and teach-me share a group because teach-me's SKILL.md points at
double-check.md, self-contain.md and style.md inside the think-twice
directory. Installing teach-me alone leaves those pointers unresolved.

Syncing from the five upstream repos is manual for now.

skills/think-twice/SKILL.md

@@ -0,0 +1,77 @@
+---
+name: think-twice
+description: >
+  Rebuild output so a reader with only this text can understand or act, with
+  every claim verified. Use when the user doesn't understand your last
+  output, asks to expand / explain / rewrite plainly / make it
+  self-contained; when shipping prose that must stand alone (handoff,
+  PR/issue body, doc, subagent brief); or when another skill needs a clarity
+  or evidence pass.
+---
+
+# Think Twice
+
+Do not polish the last draft with more jargon. Rebuild from **only what will
+appear in the output you send**, on two pillars:
+
+- **Self-contained** — the words work alone for the **cold reader**: someone
+  with this text and only what is guaranteed in front of them. Rules in
+  [self-contain.md](self-contain.md).
+- **Double-checked** — every claim in them is verified or labeled. Rules in
+  [double-check.md](double-check.md).
+
+Skip trivial one-liners the user already follows.
+
+## Second miss
+
+A rewrite already shipped and they still don't get it, or ask the same
+question in other words → invoke the **teach-me** skill (needs a reader who
+can talk back); never a third rewrite. Where teach-me is not installed, do the
+minimum it would: locate the stuck point with one question, then re-explain
+that point through a concrete example.
+
+## Process
+
+1. **Diagnose** — one primary blocker: **concept** | **scope** | **steps**
+   | **token** (undefined word or dangling reference). Fix the highest one
+   first. For proactive prose where no one is stuck yet, diagnose the blocker
+   the reader is most likely to hit.
+2. **Three questions**, answered silently: what does the reader have right now
+   (default: the cold reader)? Can they understand or act from that
+   alone? Which facts must the text pin — conclusion, scope, evidence, next
+   step?
+3. **Double-check** — verify every claim the text will make, per
+   [double-check.md](double-check.md).
+4. **Rebuild — do not patch.** Substance order: conclusion → what it is in
+   plain terms → in/out of scope when partial work matters → evidence when
+   trust matters → minimal path when action matters (success shape; on
+   failure, the next move, not only an error name). Every line obeys
+   [self-contain.md](self-contain.md).
+5. **Deliver.** Match the shape to the reader and the scene. Only two rules are
+   fixed: conclusion first, and drop anything that does not change
+   understanding or action. For a chat reply to a person, short is the
+   default. This draft shape is scaffolding, not a mould; use it, reshape it,
+   or discard it:
+
+   1. **Takeaway** — 1–3 sentences
+   2. **Need-to-know** — only terms blocking this message (omit if none)
+   3. **Next step** — only if boundaries or action matter
+
+   The slots name the substance and its order, not literal headings — they can
+   be plain sentences. Chinese prose for a human reader additionally loads
+   [style.md](style.md), an optional part.
+
+## Done when
+
+- [ ] Passes the [self-contain.md](self-contain.md) final check
+- [ ] Passes the [double-check.md](double-check.md) final check
+- [ ] Conclusion first; everything left changes understanding or action
+- [ ] Chinese human-facing output: every [style.md](style.md) rule swept, rule
+      by rule
+- [ ] A second miss went to teach-me — or, where it is not installed, to its
+      minimum — not a third rewrite
+
+## Out of scope
+
+This skill rebuilds the words; tracker/PR mechanics (linking, closing,
+labels) belong to whatever process owns them.