agents: fix review findings — thread attribution, races, rescue stall, docs, CI

Fixes from a full repo review:

- fetch-thread.sh: attribute every comment to its REAL author (@pm/@qa/… —
  agents post as their own users now); the old "🤖 @name line at the top" hint
  pointed at headers we removed, leaving every teammate comment anonymous. Also
  strip the hidden loop-prevention marker from bodies (prompt noise).
- agent.yml: per-issue concurrency group (queued, no cancel) — two quick
  comments on one issue no longer race the same ai/issue-N branch.
- rescue-pr.sh: after opening a rescue PR, hand it back into the flow with an
  unmarked @pm trigger (the pm→qa choreography previously stalled silently on
  any rescued run); drop the old "🤖 **@name**" header style; add ops to the
  token case; mark the status note with the hidden marker.
- README: token table said "@qa merges / TOKEN_QA needs write:repository" —
  inverted since the PM-orchestrated flow (@pm merges, autopilot only; @qa is
  read-only). Updated the agent table (descs, node1-ssh moved to homelab) and
  added a "How a task flows" section.
- agents.json: pm/qa descs now describe the orchestrator/reviewer roles (these
  feed the roster prompt agents route by).
- NEW ci.yml: bash -n + shellcheck(-S error) on every script, YAML-parse on
  every workflow, agents.json schema check — the ${x:-{}} brace bug would have
  been caught here before it shipped.
- install-opencode.sh: pin opencode (default 1.17.13, override via
  OPENCODE_VERSION) — a breaking release no longer takes down every agent.
- build-activity-log.sh: ollama/ollama-cloud models are subscription-billed
  (no $/token exists) — label the footer "subscription" instead of a
  misleading $0.0000; metered (anthropic) models keep the real dollar cost.
- route.sh: document that mention-priority is list-order and load-bearing for
  the flow's trigger comments.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitea/workflows/scripts/agents.json

@@ -6,7 +6,7 @@
     "skills": [
       "gitea-api"
     ],
-    "desc": "Product manager — research, plan, ask clarifying questions, and decide which dev should do the work. Comments only; never edits files."
+    "desc": "Product manager & orchestrator — plans and picks the dev, hands each finished PR to @qa for review, and reports back to the issue creator (in autopilot it merges approved PRs itself). Works from the issue thread only — comments only, never edits files, never reads the PR diff."
   },
   "junior": {
     "model": "ollama-cloud/kimi-k2.7-code:cloud",
@@ -40,7 +40,7 @@
     "skills": [
       "gitea-api"
     ],
-    "desc": "QA — verifies things work. Drives a headless browser (Playwright) to open a URL/web app, click through it, screenshot, and report bugs or confirm behavior. Comments findings; opens no PRs."
+    "desc": "QA / reviewer — reviews PRs: reads the diff, drives a headless browser (Playwright) to verify behavior, posts specific recommendations on the PR and the pass/fail verdict on the issue. Never edits code, never merges."
   },
   "ops": {
     "model": "anthropic/claude-opus-4-8",