feat(agents): wire domain reviewers into ship-feature(-lane) review stage

Route Stage 4 / review-phase reviews to ccam:backend-reviewer,
ccam:frontend-reviewer, ccam:mcp-reviewer (parallel to the generic Code
Reviewer) by which of server/, client/, mcp/ the diff touches. Give each
reviewer a parseable verdict line and project memory to match qc-local's
rigor, and update docs/LANES.md's per-stage agent description accordingly.

docs/LANES.md

@@ -1072,7 +1072,7 @@ The lane card shows a lock badge when the lane **holds** a named lock (its `lane
 
 The **ship-feature-lane** skill is the ported Shipyard driving skill for autonomous end-to-end feature pipelines in a single CCAM lane. It coordinates the entire development flow: implementation (TDD) → independent unit tests → pre-push CI gates + dev preflight → e2e testing → code review → local QC → senior gate authorization → PR push and publication → CI watch → final report.
 
-**Every stage whose job is to judge the work runs in a fresh-context subagent, never in the driving session.** The plan debate (Stage 0b), unit tests (Stage 1b), the e2e run and its triage (Stage 3), code review (Stage 4), browser QC (Stage 6), the senior gate (Stage 7), and a re-triage of CI that stayed red after a fix (Stage 10) are each dispatched with the Agent tool to a subagent that starts with an empty context and receives only artifacts it can verify itself — working directory, lane spec, diff range, commands, and the other agents' reports verbatim, never the driving session's paraphrase of why a finding was fine. The stages the driving session keeps are the ones that *do* rather than judge: intake, implementation, the mechanical gates, publishing, the CI/PR watch, and applying every fix the judges ask for. `subagent_type: fork` is explicitly forbidden for these: a fork inherits the implementing session's context, so it inherits the belief that the code is already correct. The driving session implements and applies fixes; it never grades its own work. Stages 1b/3/4 use the generic `general-purpose`/`Code Reviewer` types (nothing to install); Stages 6/7 use the lane-installed `qc-local`/`senior-gate-reviewer` agents.
+**Every stage whose job is to judge the work runs in a fresh-context subagent, never in the driving session.** The plan debate (Stage 0b), unit tests (Stage 1b), the e2e run and its triage (Stage 3), code review (Stage 4), browser QC (Stage 6), the senior gate (Stage 7), and a re-triage of CI that stayed red after a fix (Stage 10) are each dispatched with the Agent tool to a subagent that starts with an empty context and receives only artifacts it can verify itself — working directory, lane spec, diff range, commands, and the other agents' reports verbatim, never the driving session's paraphrase of why a finding was fine. The stages the driving session keeps are the ones that *do* rather than judge: intake, implementation, the mechanical gates, publishing, the CI/PR watch, and applying every fix the judges ask for. `subagent_type: fork` is explicitly forbidden for these: a fork inherits the implementing session's context, so it inherits the belief that the code is already correct. The driving session implements and applies fixes; it never grades its own work. Stages 1b/3 use the generic `general-purpose` type (nothing to install). Stage 4 uses the generic `Code Reviewer` type as its catch-all, plus — in parallel, routed by which of `server/`, `client/`, `mcp/` the diff touches — the plugin-qualified `ccam:backend-reviewer` / `ccam:frontend-reviewer` / `ccam:mcp-reviewer` domain reviewers (nothing to install; `ccam:` addressing works from any lane). Stages 6/7 use the lane-installed `qc-local`/`senior-gate-reviewer` agents.
 
 ### Getting the skill (nothing to do, if you run the plugin)