conductor(plan): mark startup_speedup_20260606 track creation committed (cd4fb045)

conductor/tracks.md

@@ -149,9 +149,9 @@ User review surfaced five outstanding UI issues, each previously attempted witho
 
 ## Remaining Backlog (Phases 3 & 4)
 
-0. [~] **Track: Sloppy.py Startup Speedup**
+0. [~] **Track: Sloppy.py Startup Speedup** `[track-created: cd4fb045]`
    *Link: [./tracks/startup_speedup_20260606/](./tracks/startup_speedup_20260606/), Spec: [./tracks/startup_speedup_20260606/spec.md](./tracks/startup_speedup_20260606/spec.md), Plan: [./tracks/startup_speedup_20260606/plan.md](./tracks/startup_speedup_20260606/plan.md)*
-   *Goal: Reduce `sloppy.py` startup time by ~2000-2400ms via (1) lazy-loading AI provider SDKs (`google.genai` 955ms, `anthropic` 430ms, `openai` 445ms) into the function that uses them, (2) lazy-loading `fastapi` in `HookServer` (~470ms), (3) lazy-loading feature-gated GUI modules (`command_palette` 244ms, `theme_nerv*` 485ms, `markdown_table` 250ms), (4) background prefetch of the default provider SDK on a daemon thread, (5) `StartupProfiler` + `/api/startup_profile` for measurement. Three-layer architecture: lazy in called function (load-bearing), bg prefetch (latency hiding), worker-process (future). Target: `import src.ai_client` < 50ms (from ~1800ms), `import src.gui_2` < 500ms (from ~3000ms), `live_gui.wait_for_server(timeout=15)` no longer times out.*
+   *Goal: Reduce `sloppy.py` startup time by ~2000-2400ms. **Main Thread Purity Invariant**: main thread (entering `immapp.run()`) never imports a module heavier than `imgui_bundle` + lean `gui_2` skeleton. **No-prefetch rule**: heavy SDKs (`google.genai` 955ms, `anthropic` 430ms, `openai` 445ms, `fastapi` 470ms) are lazy-only — paid once on first use, on the asyncio thread, not in the background. **No-new-threads rule**: all background work goes through `AppController._io_pool` (4-thread `ThreadPoolExecutor`, named `controller-io-N`); zero new `threading.Thread(...)` calls in `src/`. **Enforcement**: static `scripts/audit_main_thread_imports.py` CI gate + runtime `tests/test_main_thread_purity.py` (`sys.addaudithook` test). 9 phases, 57 tasks. Target: `import src.ai_client` < 50ms (from ~1800ms), `import src.gui_2` < 500ms (from ~3000ms), `live_gui.wait_for_server(timeout=15)` no longer times out.*
 
 0b. [x] **Track: rag_phase4_stress_test_flake_20260606** — fixed 16412ad5
    *Status: 2026-06-06 — Surfaced during post-v2 verification. Resolved: real bug, NOT a test flake. Root cause: ChromaDB collection dimension mismatch across test runs. The persistent on-disk collection (`tests/artifacts/live_gui_workspace/.slop_cache/chroma_test_stress/`) was created by a previous run with Gemini embeddings (3072-dim); the current run uses local SentenceTransformers (384-dim). `index_file()` upserts silently corrupt the collection, then `search()` fails with `Collection expecting embedding with dimension of 3072, got 384` and the AI request never reaches 'done' status, timing out the 50*0.5s = 25s poll loop. Fix: `RAGEngine._init_vector_store` now calls `_validate_collection_dim` which inspects the first existing vector's dim, compares to the current provider's output, and recreates the collection on mismatch (with a stderr warning). Regression tests added: `test_rag_collection_dim_mismatch_recreates_collection` and `test_rag_collection_dim_match_preserves_collection` in `tests/test_rag_engine.py`. This also fixes a real user-facing bug: switching embedding providers in the GUI previously caused silent corruption. Commit 16412ad5.*