feat(directives): harvest 8 directives from feature_flags/RAG/cache/knowledge styleguides + 4 new styleguides

conductor/directives/chroma_cache_path/v1.md

@@ -0,0 +1,72 @@
+# chroma_cache_path — v1
+
+**Why this iteration:** Lifted verbatim from `conductor/code_styleguides/chroma_cache.md` §"The Rule" + §"The Pre-Cleanup Pattern" (lines 5-50). This is the baseline encoding — the rule-plus-rationale-plus-anti-patterns style currently in production.
+Future variants will test alternative encodings (rule-only, before/after) against this baseline.
+
+**Source:** `conductor/code_styleguides/chroma_cache.md:5-50`
+
+---
+
+# Chroma Cache Path Styleguide
+
+## The Rule
+
+The ChromaDB persistent vector cache lives at:
+
+```
+<project_root>/tests/artifacts/.slop_cache/chroma_<collection_name>/
+```
+
+**NOT** at the per-run `tests/artifacts/live_gui_workspace_<timestamp>/` subdir.
+
+Tests that interact with RAG **MUST** pre-clean the cache to avoid persistent state from prior tests in the batched run.
+
+## Why This Rule Exists
+
+The chroma cache path is auto-derived from `RAGEngine._init_vector_store()` (`src/rag_engine.py:108-125`):
+
+```python
+db_path = os.path.abspath(os.path.join(
+    self.base_dir, ".slop_cache", f"chroma_{vs_config.collection_name}"
+))
+```
+
+`self.base_dir` is computed as `Path(active_project_path).parent`. **The trailing-slash bug**: when the test config produces a project path ending in `/` (e.g., from `os.path.join` with a trailing `/`), `Path(p).parent` returns the directory ONE LEVEL HIGHER than expected. So the chroma cache lands at `tests/artifacts/.slop_cache/` (the parent of the per-run `live_gui_workspace_<timestamp>/` subdir) instead of inside the per-run subdir.
+
+## The Pre-Cleanup Pattern
+
+RAG tests should wipe the chroma cache BEFORE pushing RAG config. The pattern is in `tests/test_rag_phase4_final_verify.py`:
+
+```python
+from pathlib import Path
+import shutil
+
+def test_phase4_final_verify(live_gui):
+    # Wipe any stale chroma from prior batched runs
+    cache = Path("tests/artifacts/.slop_cache/chroma_test_final_verify")
+    if cache.exists():
+        shutil.rmtree(cache, ignore_errors=True)
+    # ... rest of test
+```
+
+`ignore_errors=True` is required because:
+- On Windows, the chroma client may still hold file handles; `rmtree` may fail with `WinError 32` (sharing violation).
+- If a parallel xdist worker is mid-write, the rmtree can race; `ignore_errors` lets the next worker's write retry.
+
+## Anti-Patterns
+
+❌ **Assuming the cache is per-run:**
+
+```python
+def test_rag(live_gui, live_gui_workspace):
+    # WRONG: live_gui_workspace is a per-run subdir, but the chroma
+    # cache is at tests/artifacts/.slop_cache/, NOT under live_gui_workspace
+    cache = live_gui_workspace / ".slop_cache" / "chroma_test"
+    if cache.exists():
+        shutil.rmtree(cache)  # Doesn't find the actual cache
+```
+
+❌ **Not pre-cleaning at all:**
+```python
+def test_rag(live_gui):
+    # WRONG: no pre-cleanup. If a prior batched run with a different