feat: planner overseer session advisor (OMP advisor parity) (#2082)
## Summary
Adds a **session advisor** to the planner overseer so Fusion can review
live executor transcripts the way [oh-my-pi’s
advisor](https://github.com/can1357/oh-my-pi/tree/main/packages/coding-agent/src/advisor)
does — without replacing the existing lifecycle supervisor (stage watch,
retry, merge confirmation, human-control withhold).
### What ships
- **Emission guard** (`OverseerEmissionGuard`) — content-free phrase
filter, session dedupe with severity-rank escalation, one accept per
advisor update
- **Session delta runtime** — queues agent-log deltas, drains through an
advisor agent, drops backlog after 3 failures
- **Session advisor service** — model gate, level matrix (`observe` /
`steer` / `autonomous`), human-control re-check at inject,
`[session-advisor]` steering comments
- **OVERSEER.md / WATCHDOG.md** discovery for project review priorities
- **AgentLogger `onEntriesFlushed`** + poll-backed agent-log cursor for
durable deltas
- Workflow settings: `plannerOverseerAdvisorProvider` +
`plannerOverseerAdvisorModelId` (both required; empty = soft-disabled
for cost safety)
- Docs + changeset
### What does not ship (deferred)
- Multi-advisor YAML roster, mutating advisor tools, reviewer/merger
shadowing, true tool-abort interrupt
### Plan
`docs/plans/2026-07-13-001-feat-overseer-advisor-parity-plan.md`
## Enablement
1. Set workflow **Session advisor model provider** + **Session advisor
model id**
2. Oversight level `observe` (log only), `steer`, or `autonomous`
(inject)
3. Optional: add `OVERSEER.md` or `WATCHDOG.md` in the project
## Test plan
- [x] `pnpm --filter @fusion/core exec vitest run
src/__tests__/overseer-emission-guard.test.ts`
- [x] `pnpm --filter @fusion/engine exec vitest run` overseer-* unit
tests (21 tests)
- [x] Related planner-overseer / intervention regression tests
- [x] `@fusion/engine` + `@fusion/core` typecheck
- [ ] Manual: configure advisor model, run an executor task, confirm
`[session-advisor]` inject + timeline metadata when concern is raised
## Residual Review Findings
None from autofix pass (log-cursor ordering fix already committed).
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* Added an off-by-default “session advisor” that can review live
execution activity and provide severity-based guidance.
* Added project and per-task controls to enable it, including a default
enable switch and Quick Add / Task Detail toggles.
* Enhanced advisor prompting by discovering and incorporating
`OVERSEER.md`/`WATCHDOG.md` review files.
* **Documentation**
* Added architecture and settings documentation for the new
session-advisor parity behavior.
* **Bug Fixes**
* Improved fail-soft handling so advisor behavior won’t disrupt
execution.
* Fixed concurrent PostgreSQL migration startup failures.
* **Tests**
* Added coverage for advice parsing, emission guarding, runtime
behavior, and watchdog discovery.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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