feat(skills): add setup-projects-meta + using-projects-meta pair

Wraps the local projects-meta-mcp stdio server with the validated split-pair
pattern (setup-X / using-X), 4th application after context7 / wiki / tasks.

setup-projects-meta — 8-phase install: clones server repo to
~/.local/projects-meta-mcp, builds, writes ~/.config/projects-mcp/auth.toml,
clones shared wiki to ~/projects/projects-wiki/ (canon path; legacy
~/projects/.wiki is detected and migrated — old path caused the
wiki-path-mismatch bug, fixed upstream in 621a69f), registers
mcpServers.projects-meta in ~/.claude.json. Confirmation gates between
discovery and writes.

using-projects-meta — runtime policy: read tools (tasks_aggregate,
knowledge_search, meta_status, ...) and mutation tools with mandatory
two-step preview→confirm. Carries the local-first rule inline: for the
current project read .tasks/ / .wiki/ from disk; MCP cache is for *other*
projects only.

Wiki concept page concepts/projects-meta-skills.md documents the design,
the path-canon fix, and the round-trip task lifecycle across machines.

Closes [projects-meta-skills] in claude-skills (created from
DESKTOP-NSEF0UK via projects-meta-mcp).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

skills/using-projects-meta/README.md

@@ -0,0 +1,144 @@
+# using-projects-meta
+
+Runtime policy for the local `projects-meta-mcp` stdio server. Two
+responsibilities, one server:
+
+1. **Cross-project task aggregation** — reads / writes `.tasks/STATUS.md` in
+   any of the user's Gitea repos.
+2. **Shared knowledge wiki** — query / ingest a single Gitea-backed wiki at
+   `~/projects/projects-wiki/.wiki/` (clone root: `~/projects/projects-wiki/`,
+   Gitea repo: `projects-wiki`).
+
+`using-projects-meta` governs *usage* of an installed server. Initial setup
+(clone, build, `auth.toml`, MCP registration) is owned by
+[`setup-projects-meta`](../setup-projects-meta/).
+
+Full server reference:
+`mcp__projects-meta__knowledge_get slug=packages/projects-meta-mcp`.
+
+## When it triggers
+
+- User asks for cross-project state ("what's on the boards", "across all
+  projects", "что у меня на досках", "по всем проектам").
+- User wants to query / ingest the shared wiki ("check shared wiki", "search
+  projects-wiki", "ingest into shared wiki", "общая вики", "заингесть в общую").
+- User wants to create / update / close a task in *another* project from the
+  current cwd ("заведи в проекте X задачу", "close task Y in project Z").
+- User asks for sync diagnostics ("when did the cache last refresh", "are there
+  sync errors").
+- If `mcp__projects-meta__*` tools are missing, this skill delegates to
+  [`setup-projects-meta`](../setup-projects-meta/) before doing anything else.
+
+## Local-first rule (critical)
+
+For the **current** project — read disk directly (`.tasks/STATUS.md`,
+`.wiki/index.md`). The MCP cache:
+
+- May be stale (sync runs only when triggered).
+- Hides `🟢 done` by default.
+- May not contain unpushed projects.
+
+Use MCP only for **other** projects, **other** machines, or the **shared**
+wiki content. See the table below.
+
+| Question | Where to read |
+|---|---|
+| "What's the status of *this* project?" | local `.tasks/STATUS.md` |
+| "What's on all my boards?" | `mcp__projects-meta__tasks_aggregate` |
+| "Has *this* project's wiki got X?" | local `.wiki/index.md` |
+| "Has the **shared** wiki got X?" | `mcp__projects-meta__knowledge_search` |
+| "Sync state across machines?" | `mcp__projects-meta__meta_status` |
+
+## Two operation classes
+
+### Read (no confirmation)
+
+`tasks_aggregate`, `tasks_search`, `tasks_get`, `knowledge_search`,
+`knowledge_get`, `knowledge_suggest_promote`, `meta_status` — all
+side-effect-free. Call directly, cite the result.
+
+### Mutate (always two-step)
+
+`tasks_create`, `tasks_update`, `tasks_close`, `knowledge_ingest`,
+`knowledge_promote` — write to Gitea. Procedure:
+
+1. Call **without** `confirm: true` → returns dry-run preview (proposed file
+   diff + commit message).
+2. Show the preview to the user. Wait for explicit "ok" / "go" / "поехали".
+3. Re-call with `confirm: true` → committed.
+
+**Never inline `confirm: true` on the first call.** A trigger phrase is
+permission to plan, not to commit.
+
+## Tool quick reference
+
+### Read
+
+| Tool | Required args | Purpose |
+|---|---|---|
+| `mcp__projects-meta__tasks_aggregate` | — | All active tasks across cached projects |
+| `mcp__projects-meta__tasks_search` | `query` | Substring search across slug + next_action |
+| `mcp__projects-meta__tasks_get` | `project` | Raw STATUS.md of one project (cache snapshot) |
+| `mcp__projects-meta__knowledge_search` | `query`; opt `domain`, `limit` | Shared-wiki search; default domain auto-detected from cwd |
+| `mcp__projects-meta__knowledge_get` | `slug` | Full text of one wiki page |
+| `mcp__projects-meta__knowledge_suggest_promote` | — | Local `.wiki/concepts/` candidates for shared promotion |
+| `mcp__projects-meta__meta_status` | — | Sync diagnostics (cache age, project / page / error counts) |
+
+### Mutate (need `write:repository` Gitea scope)
+
+| Tool | Required args | Effect |
+|---|---|---|
+| `mcp__projects-meta__tasks_create` | `target_project`, `slug`, `description`, `next_action` | Append block to target's `.tasks/STATUS.md` via Gitea commit |
+| `mcp__projects-meta__tasks_update` | `target_project`, `slug` + ≥1 mutable field | Sha-based optimistic lock; 422 on conflict |
+| `mcp__projects-meta__tasks_close` | `target_project`, `slug` (+ opt `note`) | Marks task 🟢 done with identity-footer |
+| `mcp__projects-meta__knowledge_ingest` | `target_project`, `type`, `slug`, `body` | Three commits: `<type>/<slug>.md` + `index.md` + `log.md` |
+| `mcp__projects-meta__knowledge_promote` | `target_project`, `slug`, `body` | Move `raw/<slug>.md` → `sources/<slug>.md` |
+
+`type` ∈ `entities` / `concepts` / `packages` / `sources` / `raw`.
+`target_project` = Gitea repo name, or `_meta` (meta-tasks / meta-wiki repos
+from `auth.toml`).
+
+## Common mistakes
+
+- **Reading current project's tasks via `tasks_get`.** Read `.tasks/STATUS.md`
+  on disk; the MCP cache is for *other* projects.
+- **Inlining `confirm: true` on first call.** Always preview first; show user;
+  only then `confirm: true`.
+- **Confusing the local `.wiki/` with the shared `projects-wiki`.** They are
+  two different stores. `using-wiki` operates on the local one;
+  `using-projects-meta` queries / ingests the shared one.
+- **Acting on stale `tasks_aggregate`.** If `meta_status.age_seconds` > 3600,
+  either run `node dist/sync.js` (in `~/.local/projects-meta-mcp`) or warn the
+  user about staleness.
+- **Vague `knowledge_search` queries.** "auth" returns noise. Multi-word,
+  specific queries return targeted snippets.
+- **Wrong `type` on `knowledge_ingest`.** Mis-typed pages land in the wrong
+  section and break `index.md`. Pick from the five canonical types.
+
+## When NOT to use
+
+- The current project's own tasks — read `.tasks/STATUS.md`.
+- The current project's own wiki — read `.wiki/`.
+- Library / framework documentation — that's [`using-context7`](../using-context7/).
+- Repo-internal code search — that's `Glob` / `Grep`.
+- One-off git history questions — `git log`.
+
+## Install
+
+From the repo root:
+
+```bash
+bash scripts/install.sh using-projects-meta
+```
+
+Works on Windows under git-bash, Linux, macOS.
+
+## See also
+
+- [`setup-projects-meta`](../setup-projects-meta/) — companion, owns server
+  install + MCP registration.
+- [`using-context7`](../using-context7/) — sister skill for library docs (same
+  using-X structure).
+- [`using-tasks`](../using-tasks/), [`using-wiki`](../using-wiki/) —
+  per-project policies for in-repo `.tasks/` and `.wiki/`. Orthogonal to this
+  skill; together they cover both per-project and cross-project state.