docs(lanes): document ccam lanes agents install (E3)

docs/LANES.md

@@ -988,11 +988,9 @@ The skill frontloads all clarifying questions once, then runs unattended. The on
 - **9 (Ticket)**: Ticket-filing integration not yet built — this stage is skipped entirely.
 - **13 (Post-merge verification)**: Dev-CI-wait and dev-QC integrations are off — the stage transitions immediately to `done` with a note explaining the gap.
 
-**Stages agent-gated** (will block until the agents-port task lands):
-- **6 (Browser QC)**: Requires the `qc-local` agent to drive local Playwright QC against the booted lane stack.
-- **7 (Senior gate)**: Requires the `senior-gate-reviewer` agent to authorize feature merge.
+**Stages 6 and 7 are now unblocked** — run `ccam lanes agents install` once per lane (see "Installing the QC/gate agents" below) before a lane's first run through Stage 6. A lane that reaches Stage 6/7 without having installed the agents will fail to find the `qc-local`/`senior-gate-reviewer` subagent type; install and re-run.
 
-Until these agents are ported, a lane reaching Stage 6 or 7 will be marked `blocked` with a note. See [the skill text](../.claude/skills/ship-feature-lane/SKILL.md) for the full pipeline definition.
+See [the skill text](../.claude/skills/ship-feature-lane/SKILL.md) for the full pipeline definition.
 
 ### QC boot flag and profile integration
 
@@ -1035,6 +1033,20 @@ GENERATED_MERGE_PATHS="api/openapi.json api/client.ts"
 
 `MIGRATIONS_DIR` enables the collision preflight against a numbered-migrations directory. `GENERATED_MERGE_PATHS` gives the listed files a keep-ours merge driver (never hand-merged) and folds the profile's `regen` hook output into the sync commit — the single most common cross-lane conflict, for a repo that generates an API contract/client.
 
+### Installing the QC/gate agents: agents install
+
+Stage 6 (browser QC) and Stage 7 (senior GO/NO-GO gate) run as subagents — `qc-local` and `senior-gate-reviewer` — that must exist in the lane's own `.claude/agents/` before the skill can launch them:
+
+```bash
+ccam lanes agents install
+```
+
+Writes both agent templates into `<lane>/.claude/agents/` and adds that directory to the lane's local `.git/info/exclude` (never the tracked `.gitignore` — this is a per-clone runtime concern, not an app-repo change). Idempotent and never automatic, the same shape as `ccam lanes proof-link` — a session installs the agents explicitly, once, before a lane's first run through Stage 6/7 (or after a CCAM upgrade ships updated templates — reinstalling overwrites, it doesn't merge).
+
+**Credentials are not embedded.** Unlike Shipyard's original per-lane agent generation, these templates carry no QA account credentials — this repo has no seeded-QA-account system yet. `qc-local` degrades gracefully: if it hits a login page with no credentials block present, it reports `LOCAL-QC: FAIL — login required, no seed-account mechanism configured for this profile` rather than guessing.
+
+**`ticketer`, `dev-qc`, and `pr-reviewer`** are not ported yet — the first two are invoked only by Stages 9/13, which are hardcoded-skipped pending F's integrations; the third isn't referenced anywhere in this skill's text.
+
 ### Pipeline template: ship-feature (16 node stages)
 
 The skill uses the `ship-feature` pipeline template, which defines the following 16 stages (node IDs):