Fix memory system bugs: deterministic summary id, skip legacy extraction ...

- _summary.py: replace non-deterministic hash() with zlib.crc32 so
  summary id stays stable across server restarts, preventing duplicate
  summary rows.
- extractor.py: skip memory extraction for legacy sessions (user_id=None)
  — ON CONFLICT(user_id, category, key) does not catch NULL duplicates
  in PostgreSQL (NULL != NULL).
- sessions.py: _process_stale_sessions skips legacy sessions.
- _facts.py: remove dead code (user_clause/user_param variables).
- test_extractor.py: add user_id to test sessions + new test for
  legacy session skip.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Fix WebSocket 403 — bypass FastAPI Depends for WS auth ...

- websocket.py: resolve user by calling get_current_user_ws directly
  inside the handler instead of using Depends(). This avoids FastAPI
  returning HTTP 403 on the upgrade request when auth resolution fails.
- websocket.py: accept WebSocket before access check, close with 4003
  for auth failures instead of HTTP 403.
- auth/deps.py: remove debug logging from get_current_user_ws.
- tests/conftest.py: monkeypatch get_current_user_ws directly since
  Depends() is no longer used on the WebSocket endpoint.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Multi-user auth via gnexus-auth OAuth + hybrid role/permission model ...

- Integrate gnexus-auth-client-py (GAuthClient) for OAuth flow, token refresh,
  and webhook parsing
- Add navi/auth/ package: User model, Fernet encryptor, client singleton,
  deps (get_current_user, require_admin, require_permission)
- New tables: navi_users, user_auth_sessions (auto-created on startup)
- Session/memory isolation by user_id with legacy NULL support
- Cookie-based auth proxy: /auth/login, /callback, /logout, /me
- Webhook receiver /webhooks/gnexus-auth handling user events, global logout,
  session revocation, role/permission changes
- Admin endpoints (/admin/*) gated by role + permissions
- Webclient auth store with isAdmin/hasPermission guards
- Admin-only profile filtering in /agents/profiles
- 200/200 tests passing

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Allow subagents to use selected profiles

Paginate session list loading

Refine 3D modeler workflow

Disable thinking stalls for 3D subagents

Improve 3D modeling validation prompts

Add artifact source previews

Improve content publishing UX

Complete phase 7 regression test coverage

Add regression tests for content publishing and LLM timeouts

Add context provider registry all accessor

Align Ollama HTTP timeout with LLM timeouts

Clarify share file publishing boundaries

Add 62 tests across all planned phases + fix integration flakiness ...

- Phase 3: 19 API route integration tests (health, agents, sessions, messages)
- Phase 3: 7 WebSocket integration tests (connect, send, replay, invalid, stop)
- Phase 4: 9 agent tests (_check_context_size, _iter_stream_guarded)
- Phase 4: 5 planning tests (_parse_plan_steps)
- Phase 5: 22 tool tests (filesystem 13, code_exec 5, terminal 4)
- Fix flaky integration tests by patching module-level singletons
  (_session_store, _registries, _workers) instead of getter functions,
  because FastAPI Depends() captures the original function at import time.
- Update docs/testing.md coverage table (150 total tests)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Phase 2 — Memory store + extractor unit tests ...

- tests/conftest_factory.py: add FakeRecord, FakeConnection, FakePool, make_store_with_pool
- tests/unit/memory/test_store.py: 18 tests for upsert, vector/ILIKE search, delete, list, count, summary, session state, backfill
- tests/unit/memory/test_extractor.py: 11 tests for JSON extraction, invalid JSON, empty response, tool result truncation, summary regeneration
- docs/testing.md: update coverage status, add FakePool usage example

88 total tests passing (59 + 29).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Bootstrap test suite — Phase 1 unit tests ...

- docs/testing.md: testing strategy, mock strategy, phase breakdown
- tests/conftest.py: autouse fixture to reset navi.config.settings per test
- tests/conftest_factory.py: FakeLLMBackend, FakeTool, make_profile, make_registry helpers
- tests/unit/core/test_events.py: wire serialization for all 15 event dataclasses
- tests/unit/core/test_compressor.py: should_compress, partition_messages, format_for_summary, compress_context
- tests/unit/core/test_registry.py: ToolRegistry, ProfileRegistry, BackendRegistry
- tests/unit/core/test_context_builder.py: system prompt caching, persona injection, goal anchor, iteration budget
- tests/unit/profiles/test_base.py: Pydantic model coercion, defaults, extra fields
- navi/core/context_builder.py: use module-level `import navi.config` instead of `from navi.config import settings` so tests can swap the singleton

59 tests passing.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>