[docs] sync_branch prompt + behind-base guidance (Phase B3)

Update every behind-base/rebase guidance surface to reflect the B1
sync_branch dev verb + B2 i_am_done behind-base gate: devs now self-rebase
through the gate instead of escalating a plain behind-base condition; PMs
still escalate cell/root integration branches (they have no rebase verb).

- developer.md: sync_branch in the verb table; 'When your branch is behind
  its base' rewritten — call sync_branch, do NOT i_am_blocked a plain
  behind-base; conflicts → resolve by hand, commit, sync_branch again.
- cell_pm.md: delegate signature gains intends_to_touch/adds_migration/
  touches_shared/depends_on + a 'Collision surface' section (fill it on every
  code subtask so sibling dev tasks that touch the same files sequence into a
  conflict-free order — the 2026-06-27 out-of-order break fix); behind-base
  section steers devs to sync_branch, PMs escalate only the integration branch.
- main_pm.md: behind-base section — dev leaf = dev's sync_branch; cell/root
  integration branch = escalate_up.
- RAG git-errors.md / blocked-tools.md: devs sync_branch, PMs escalate.
- docs/troubleshooting/common-issues.md: leaf self-rebases; integration branch
  still escalates to operator.
- CLAUDE.md verb surface: developer gains sync_branch.
- agents/prompts/_generated/*: regenerated via scripts/regenerate_verb_tables.py
  — adds sync_branch to the dev table AND catches the generated tables up to
  the S1/S2 delegate sequencing params + meltdown-fix note top-level params
  (the derived files had drifted stale vs the already-committed schemas).

Docs/prompts only — no code. ruff + mypy roboco/ tests/ clean.

agents/prompts/_generated/cell_pm.md

@@ -8,7 +8,7 @@
 | Verb | Body schema |
 |------|-------------|
 | `complete` | `complete(task_id: UUID, notes: str)` |
-| `delegate` | `delegate(parent_task_id: UUID, title: str, description: str, assigned_to: str, team: str, task_type: str, nature: str, estimated_complexity: str, acceptance_criteria: list[str], project_id: UUID | None = None, covers_parent_criteria: list[str] | None = None)` |
+| `delegate` | `delegate(parent_task_id: UUID, title: str, description: str, assigned_to: str, team: str, task_type: str, nature: str, estimated_complexity: str, acceptance_criteria: list[str], project_id: UUID | None = None, covers_parent_criteria: list[str] | BeforeValidator(func=<function coerce_str_list at 0x109dbdee0>, json_schema_input_type=PydanticUndefined) | None = None, intends_to_touch: list[str] | BeforeValidator(func=<function coerce_str_list at 0x109dbdee0>, json_schema_input_type=PydanticUndefined) | None = None, adds_migration: bool = False, touches_shared: bool = False, depends_on: list[UUID] | None = None)` |
 | `escalate_up` | `escalate_up(task_id: UUID, reason: str)` |
 | `give_me_work` | `give_me_work()` |
 | `i_am_idle` | `i_am_idle()` |
@@ -24,7 +24,7 @@
 
 | Tool | Body schema |
 |------|-------------|
-| `note` | `note(text: str, scope: str = 'note', task_id: UUID | None = None, title: str | None = None, context: str = '', options: list[str | str] | None = None, chosen: str = '', rationale: str = '', consequences: list[str] | None = None, what_done: str = '', what_learned: str = '', what_struggled: str = '', next_steps: list[str] | None = None, section: str | Any | None = None)` |
+| `note` | `note(text: str, scope: str = 'note', task_id: UUID | None = None, title: str | None = None, context: str = '', options: list[str | str] | None = None, chosen: str = '', rationale: str = '', consequences: list[str] | None = None, what_done: str = '', what_learned: str = '', what_struggled: str = '', next_steps: list[str] | None = None, section: str | Any | None = None, done: str = '', next: str = '', where_to_look: list[str] | None = None)` |
 | `say` | `say(channel: str, text: str, task_id: UUID | None = None)` |
 | `dm` | `dm(recipient: str, text: str, task_id: UUID | None = None, skill: str | None = None)` |
 | `notify` | `notify(target: str, text: str, priority: str = 'normal', task_id: UUID | None = None)` |