v0.20.0

Neo gains a long-lived presence: an out-of-band synthesis observer supervised by CAR's agent runtime, a live A2UI memory inspector that exposes both observer cycles and FactStore state to any conformant renderer, plus quieter foundational work on project-ID stability, metrics ergonomics, and a new fact-domain taxonomy.

Added

• Async synthesis observer (neo memory observer {start|stop|status|kick}) — a per-project background process that runs synthesize_reviews on a wall-clock cadence (default 5 min), decoupled from the request path. Additive: the inline triple-trigger gate keeps firing too; the observer just makes synthesis more frequent. Lifecycle is owned by CAR's agent supervisor (car-runtime ≥ 0.17.0): spawn, restart-on-failure, log redirection to ~/.car/logs/, clean SIGTERM shutdown, and auto-start at daemon boot via the persisted spec in ~/.car/agents.json. Tunables: NEO_OBSERVER_INTERVAL_SECONDS, NEO_OBSERVER_COOLDOWN. Status surfaces CAR's raw state (running | stopped | starting | backoff | errored) so restart-loops are diagnosable. Hard footgun: the interpreter must not live under a world-writable directory (/tmp, /private/tmp, /var/tmp, /dev/shm) — the CAR daemon rejects such commands for security.
• A2UI memory inspector surface (neo.a2ui) — a per-project A2UI v0.9 surface (neo-<project_id8>) registered with the running car-server daemon so any conformant renderer (CarHost.app, future webviews) can inspect Neo's state live. Two tabs: Observer (status badge, pid, last cycle, recent cycles list, Kick/Stop buttons) and Memory (valid fact count, by kind, by scope, probation count). Both populate from the same FactStore load the observer's synthesis cycle already does — zero hot-path cost. Kick/Stop buttons emit a2ui.action notifications which the observer dispatches to kick_observer / stop_observer, closing the loop with CAR's supervisor. Activation: auto when 127.0.0.1:9100 is reachable; silent no-op otherwise.
• Fact.domain taxonomy — optional free-form area tag orthogonal to FactKind. memory.models.SUGGESTED_DOMAINS (code-style, testing, git, debugging, workflow, security, file-patterns, architecture, performance) is the recommended vocabulary; any string is valid. retrieve_relevant(..., domain=...) filters by exact match; domain=None returns all facts including unset ones; a specific filter excludes domain-unset facts.
• NEO_PROFILE metrics gating (off | minimal | standard | strict) replaces the single-knob NEO_METRICS=off. minimal emits only lm_call (audit trail without per-retrieval volume); standard emits everything (default, matches prior behavior); strict is reserved for future verbose events. NEO_METRICS=off remains a hard kill-switch that overrides NEO_PROFILE.

Changed

• project_id is now hashed from the normalized git remote URL (scope._compute_project_id), not the codebase root path. The same repo on different clones / worktrees / machines now resolves to the same project ID. Falls back to a path hash when no remote is configured. Legacy path-hashed fact and watermark files in ~/.neo/facts/ are renamed in place on FactStore init (store._migrate_legacy_project_id_files) — transparent for upgrades.
• car-runtime>=0.17.0 is now the floor for the [car] extra (bumped from >=0.9.0). The observer's agents_* lifecycle calls require the WS-routing fix that landed in v0.17.0 (Parslee-ai/car-releases#54) — earlier car-runtime versions still work for CarAdapter-only use, but neo memory observer start will refuse them with an actionable error pointing at the upgrade path.

Fixed

• Observer's agents_list shape parsing — the CAR ManagedAgent shape uses a status string (running | stopped | starting | backoff | errored), not a running bool. Initial port checked existing.get("running") which was always falsy — meaning stop_observer returned "not_running" before ever calling agents_stop, leaking the supervised child. Fixed; observer_status now surfaces CAR's raw status verbatim. Regression test added.
• asyncio missing from the observer module-scope import. Surfaced only after the daemon spawn — caught by the live A2UI integration test, not unit tests.
• a2ui.apply envelope was wrapped under params={"envelope": …} instead of being passed as the envelope directly, silently creating an empty surface. Wire-shape regression test added (tests/test_a2ui.py::TestWireShape).
• pytest-asyncio added to [dev] extra — the new async a2ui tests failed in CI because the plugin was only in my local venv. Adds pytest-asyncio>=0.21.0 to the manifest.
• websockets>=12.0 added to [car] extra — needed by neo.a2ui.DaemonClient to speak JSON-RPC over the daemon's WebSocket (the Python car_runtime.a2ui_* helpers are in-process only).

Docs

• CLAUDE.md / AGENTS.md gain bullets for: project-ID hashing + migration, domain taxonomy, profile gating, observer (incl. tunables and the world-writable-command footgun), and the A2UI surface architecture (including why the in-process car_runtime.a2ui_* helpers don't suffice).
• New docs/solutions/async-observer.md design proposal — borrows process-lifecycle ideas from ECC's continuous-learning-v2 observer, ported onto CAR's agents_* supervisor. Includes an as-built note pointing readers at src/neo/memory/observer.py.