feat(agents): W2/S2 doc pipeline two-mode + last inline conversions (BDR-077)

doc-syncer: ONE agent, TWO dispatch modes around the dispatcher's gate —
MODE: audit (model="opus" call-site override, READ-ONLY, drafts + PATCH
PLAN) / MODE: patch (sonnet pin, applies the APPROVED plan, shape oracle
w/ revert-on-fail, emits CHANGE SUMMARY + PATCHED_FILES). Deviation from
plan's 2-file split, per the challenge's own commit-changer mode
precedent: zero text duplication, zero lock moves. Fixes a LATENT DEFECT:
/doc dispatched an agent whose STEP 8 gate could never fire (dispatched
agents cannot ask) — the gate now lives in the dispatcher (DISPATCHER
PROTOCOL section). doc-commit.md consumes the patcher's CHANGE SUMMARY
(the in-thread context now crosses the dispatch boundary, LRN-126).
Consumers rewired: /doc (audit→gate→patch→commit), onboard (audit
report-only, opus), doc-commit steps in bugfix/hotfix/feat/ship-feature/
init-project(5b+10c); scaffolder loses PHASE 6 (README = init 5b's job);
scaffolder + onboarder now DISPATCHED in init-project/onboard (pins live,
was inline on session model). In-wave planted-drift smoke PASSED
end-to-end, disk-verified (audit caught npm-run-dev drift → [MINOR] plan
→ patch applied → summary crossed). Census §14-15 (103 pass), make test
exit 0. Typed plugin-probe dispatch resolution verified post-restart.

skills/onboard/SKILL.md

@@ -89,7 +89,11 @@ STOP. La réponse détermine si STEP 1 tourne une fois (A) ou N fois (C) ou avec
 
 ## STEP 2 — BASELINE CONFIG (onboarder agent)
 
-Load `$HOME/.claude/agents/onboarder.md`. Passer un BRIEF minimal issu du filesystem scan :
+Dispatch `Agent(subagent_type="onboarder")` (pin sonnet — BDR-077 : config
+templating = exécution, plus jamais inline sur le modèle de session). Un
+BLOCAGE (clé manquante, CLAUDE.md existant) revient en rapport — l'agent ne
+peut pas te demander ; TU arbitres ici puis re-dispatches. Passer un BRIEF
+minimal issu du filesystem scan :
 - `archetype` (depuis STEP 1)
 - `project_name` (depuis package.json/pyproject.toml/README.md/dir name)
 - `stack` (depuis manifests détectés)
@@ -531,9 +535,11 @@ flux de dev sont deux formes distinctes ([[BDR-050]] pipeline dev ≠ audit).
 ```
 Agent(
   subagent_type="doc-syncer",
+  model="opus",
   description="Onboard — doc drift audit only",
   prompt="""
-  REPORT-ONLY mode — NO edits, NO auto-sync.
+  MODE: audit — REPORT-ONLY, NO edits, NO auto-sync (no patch dispatch
+  follows: the report feeds the onboard backlog).
   Target: full project at <PROJECT_ROOT>.
   Scope:
     1. README drift (build/test commands, install steps, usage examples vs actual code)