docs(agents): add pr-review and triage-prs skills, always-on communication guidance

- pr-review: maintainer-proxy verdict review (decline / push-back /
  merge-then-fix / merge) with ready-to-post actions, product-fit
  escalation, ache salvage on declines, and merge-base diff measurement
- triage-prs: batch queue triage pipeline (mechanical sweep, duplicate
  clusters, fan-out verdict reviews, approved batch actions) with
  canonical message templates
- AGENTS.md: new Communication section replaces the always-load
  communication-style mandate; the skill keeps a trigger-based
  description for editing human-facing text
- register all project skills in .claude/skills (only 6 of 17 were
  linked, leaving most skills undiscoverable)

.agents/skills/triage-prs/SKILL.md

@@ -0,0 +1,63 @@
+---
+name: triage-prs
+description: Load when asked to triage, clean up, batch-process, or work through the open PR queue or backlog — covers the mechanical sweep (stale, conflicts, duplicates), fan-out verdict reviews, and approved batch actions.
+---
+
+Turn an unbounded PR queue into a short list of maintainer decisions. The pipeline has three phases; **no GitHub write happens in any phase without the maintainer approving that specific batch** — present verdicts and drafted messages first, act on their word.
+
+Companion: each substantive review inside phase 3 applies the `pr-review` skill; this skill owns only the batch mechanics around it.
+
+## Phase 1 — Mechanical sweep (no judgment, no LLM verdicts)
+
+Fetch all open PRs with `gh` (the repo is `openchamber/openchamber`). Two measurement rules learned the hard way:
+
+- **Staleness is the last commit date on the branch, never `updatedAt`** — bots bump `updatedAt` with every comment and label. Fetch last-commit dates with batched GraphQL (`commits(last: 1)`), ~50 PRs per query.
+- `gh pr list` silently defaults to 30 rows — always pass `--limit` above the real queue size and print the resulting count.
+
+Bucket every non-draft PR:
+
+| Bucket | Condition | Action template |
+|---|---|---|
+| Dead | merge conflict AND no author commit in >30 days | close with **stale-close** |
+| Conflicted-active | merge conflict, author committed within 30 days | comment **rebase-request**, leave open |
+| Clean | mergeable | phase 3 review pool |
+| Draft | `isDraft` | untouched until marked ready |
+
+Then detect **duplicate clusters** across the survivors: pairs with high title-token overlap or high changed-file overlap. For each cluster recommend one keeper (prefer: mergeable over conflicted, references an issue, smaller diff, earlier author — a later near-identical body is likely a regenerated copy of the earlier PR, and the earlier author keeps the credit); the rest close with **duplicate-close**.
+
+Deliver the sweep as one report (counts per bucket, per-bucket tables with number/title/author/size/last-commit-age/areas, clusters with keeper recommendations) and stop for approval.
+
+## Phase 2 — Approved batch actions
+
+Execute the approved closes/comments with retries and ~1–2s spacing between calls. Log every result; report exact ok/fail counts and re-verify the open-PR total afterwards. Branch protection may reject merges — `--admin` is available and accepted for maintainer-approved merges; a merge that becomes conflicted mid-batch (usually CHANGELOG collisions from the batch's own merges) can be resolved in a temporary worktree and pushed to the contributor's branch when `maintainerCanModify` is true.
+
+## Phase 3 — Verdict reviews
+
+Split the clean pool smallest-first (tiny diffs are fast wins and most likely mergeable). Fan out subagents in batches of ~10 PRs each; every subagent receives the full `pr-review` skill text as its instructions plus its PR numbers, reads real diffs (`gh pr view`, `gh pr diff`) and the local checkout, and returns per-PR verdict blocks in the skill's output format.
+
+Consolidate into a single report grouped by verdict — MERGE, MERGE-THEN-FIX, PUSH-BACK (with the drafted lists), DECLINE (with the drafted close comments), plus every "needs your hands" line — and stop for approval. After approval: post/merge per verdict, and queue MERGE-THEN-FIX follow-ups as in-house work.
+
+If a batch subagent skips a PR, notice (count outputs against inputs) and re-dispatch the gap.
+
+## Message templates
+
+Canonical texts — reuse verbatim, adjusting only bracketed parts. Tone rules: honest about the backlog, no "feel free to reopen", thanks proportional to real effort.
+
+**stale-close**
+> Closing this as stale: the branch has merge conflicts with `main` and hasn't been updated in over a month. The codebase has moved on significantly since this was opened, so this change would need to be redone against the current state anyway.
+
+**rebase-request**
+> Sorry for the review backlog — the queue is currently far beyond what a single maintainer can handle. This PR has merge conflicts with `main`, and I can only review PRs that merge cleanly. If you're still interested in landing this, please rebase — conflicted PRs without activity will eventually be closed as stale.
+
+**duplicate-close**
+> Closing as a duplicate of #[N], which will be reviewed instead[: one-clause reason it was kept].
+
+**oversized-split** (single PR bundling several concerns)
+> Closing this one. It bundles several unrelated concerns — [list] — into a single [size] change across [n] files, which isn't reviewable in this form. If you'd like to pursue [the worthwhile part], please open an issue first to agree on scope, and then a focused PR for that single concern.
+
+**russian-locale** (any PR adding Russian localization — this is a standing decision, apply without re-asking)
+> We’re not accepting Russian localization for OpenChamber.
+>
+> This is an intentional maintainership decision due to Russia’s ongoing war against Ukraine. We don’t want to ship or maintain Russian UI support.
+>
+> Closing.