🐛 Add idle-behavior guideline to pr-reviewer and pr-logbook

[hcross]

Adds a short Idle behavior section to the pr-reviewer agent and the pr-logbook skill so teammates confirm availability in one sentence instead of re-summarising a completed task on every idle wake-up. Implements #96.

How to read this PR?

Start with the canonical sources — they hold the contract:

1. community-config/agents/pr-reviewer/AGENT.md — new ## Idle behavior section, provenance 1.0.0 → 1.0.1.
2. community-config/skills/pr-logbook/SKILL.md — new ## Idle behavior section, provenance 1.1.1 → 1.1.2.

The matching edits under .claude/ and .gemini/ are byte-for-byte mirrors of the canonical change, kept in lock-step so the three distribution trees do not drift. The version bumps are PATCH per community-config/skills/pr-logbook/SKILL.md → Cross-cutting: skill / agent source version bumps (wording-only addition).

How to test this PR?

1. Re-read the new ## Idle behavior block in each of the six touched files and confirm the wording is identical across the canonical / .claude/ / .gemini/ triplet for each component.
2. From the repo root, run bash scripts/check-skill-versions.sh (or task check-skill-versions if available) — both bumped sources must pass the version-bump gate.
3. Spawn a pr-reviewer or pr-logbook agent, let it complete its assigned task, then send an empty wake-up. Expected: a single-sentence availability confirmation, not a re-summary of the completed work.

Detailed description (for agents)

• community-config/agents/pr-reviewer/AGENT.md: appended ## Idle behavior section before ## Friction reporting; bumped metadata.provenance.version from 1.0.0 to 1.0.1.
• community-config/skills/pr-logbook/SKILL.md: appended ## Idle behavior section at end-of-file; bumped metadata.provenance.version from 1.1.1 to 1.1.2.
• .claude/agents/pr-reviewer/AGENT.md, .gemini/agents/pr-reviewer.md: byte-mirror of the canonical AGENT change.
• .claude/skills/pr-logbook/SKILL.md, .gemini/skills/pr-logbook/SKILL.md: byte-mirror of the canonical SKILL change.
• No code, no scripts, no schema changes — documentation-only behavior guideline. Total: 6 files, +51 / -6 (git diff --stat origin/main..HEAD).

The friction is documented in #96 and the implementation logbook is appended as a comment on the same issue per the upstream-issue logbook rule (community-config/skills/pr-logbook/SKILL.md → Logbook entries).

Implements #96.

[hcross]

Verdict: APPROVE (posted as COMMENT — GitHub blocks self-approval)

Cold-start review. Documentation-only change implementing #96. No blocking issues found; the verdict is approve but submitted as COMMENT because the PR author is also the reviewer's account.

Correctness

• The change adds an ## Idle behavior section to two canonical sources and propagates the exact same block to the four mirror files under .claude/ and .gemini/. Each mirror is byte-identical to its canonical sibling, matching the PR claim that the trees are kept in lock-step.
• Section placement is consistent: in community-config/agents/pr-reviewer/AGENT.md it sits between ## Out of scope and ## Friction reporting; in community-config/skills/pr-logbook/SKILL.md it sits at end-of-file after ## Friction reporting. Both placements are coherent with the surrounding structure.
• The guideline matches the friction described in issue #96 ("teammates re-confirm completed tasks in subsequent idle notifications"). The prescribed remedy — single-sentence availability confirmation — is exactly what the curator-clustered issue body recommended.

Convention compliance

• Title 🐛 Add idle-behavior guideline to pr-reviewer and pr-logbook follows the Gitmoji convention from AGENTS.md.
• Branch fix/issue-96-teammate-idle-confirmation matches the fix/ prefix rule.
• PR body contains all four required sections: human summary, How to read this PR?, How to test this PR?, Detailed description (for agents).
• Logbook: the PR body states the logbook is appended as a comment on #96 per the upstream-issue rule in community-config/skills/pr-logbook/SKILL.md. Issue #96 is open and carries the logbook label.
• Version bumps are present and PATCH-scoped (wording-only addition): AGENT 1.0.0 → 1.0.1, SKILL 1.1.1 → 1.1.2. Mirrors carry the same bump.

Test coverage

• Documentation-only PR; no executable code changed. The PR's How to test step 3 (spawn an agent, idle-wake, observe single-sentence reply) is a reasonable manual acceptance check; nothing else is testable.

Linter findings

• lint-markdown.sh community-config/agents/pr-reviewer/AGENT.md community-config/skills/pr-logbook/SKILL.md → exit 0, no output.
• lint-skill.sh community-config/skills/pr-logbook/SKILL.md → exit 0, no output. Version bump vs origin/main detected, all required frontmatter keys present.
• lint-skill.sh community-config/agents/pr-reviewer/AGENT.md → exit 1, but the findings (missing required frontmatter key: name / description / license / compatibility) are a pre-existing script/schema mismatch, not a regression: this linter validates SKILL.md frontmatter (which requires license and compatibility), while AGENT.md uses a lighter schema. Running it against origin/main:community-config/agents/pr-reviewer/AGENT.md produces the same output. The PR's own version-bump check passes on AGENT (1.0.0 → 1.0.1 detected). Not blocking — worth a follow-up to either add a dedicated lint-agent.sh or teach lint-skill.sh to branch on type: agent.