Sprint 0-1: Python indexer, TS plugin scaffolding, and test suite

## What's new

**Python indexer (`python/obsidian_rag/`)** — full pipeline from scan to LanceDB:
- `config.py` — JSON config loader with cross-platform path resolution
- `security.py` — path traversal prevention, HTML stripping, sensitive content detection, dir allow/deny lists
- `chunker.py` — section-split for journal entries (date-named files), sliding-window for unstructured notes
- `embedder.py` — Ollama `/api/embeddings` client with batched requests and timeout/error handling
- `vector_store.py` — LanceDB schema, upsert (merge_insert), delete, search with filters, stats
- `indexer.py` — full/sync/reindex pipeline orchestrator with progress yields
- `cli.py` — `index | sync | reindex | status` CLI commands

**TypeScript plugin (`src/`)** — OpenClaw plugin scaffold:
- `utils/` — config loader, TypeScript types, response envelope factory, LanceDB client
- `services/` — health state machine (HEALTHY/DEGRADED/UNAVAILABLE), vault watcher with debounce/batching, indexer bridge (subprocess spawner)
- `tools/` — 4 tool stubs: search, index, status, memory_store (OpenClaw wiring pending)
- `index.ts` — plugin entry point with health probe + vault watcher startup

**Config** (`obsidian-rag/config.json`, `openclaw.plugin.json`):
- 627 files / 3764 chunks indexed in dev vault

**Tests: 76 passing**
- Python: 64 pytest tests (chunker, security, vector_store, config)
- TypeScript: 12 vitest tests (lancedb client, response envelope)

## Bugs fixed

- LanceDB `tags` column filter: `LIKE '%tag%'` → `list_contains(tags, 'tag')` (List<String> column)
- LanceDB JS `db.list_tables()` returns `ListTablesResponse` object, not plain array
- LanceDB JS result score field: `_score` → `_distance`
- TypeScript regex literal with unescaped `/` in path-resolve regex
- Python: `create_table_if_not_exists` identity check → name comparison

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

python/pyproject.toml

@@ -0,0 +1,35 @@
+[build-system]
+requires = ["setuptools>=68.0"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "obsidian-rag"
+version = "0.1.0"
+description = "RAG indexer for Obsidian vaults — powers OpenClaw's obsidian_rag_* tools"
+requires-python = ">=3.11"
+dependencies = [
+    "lancedb>=0.12",
+    "httpx>=0.27",
+    "pyyaml>=6.0",
+    "python-frontmatter>=1.1",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=8.0",
+    "pytest-asyncio>=0.23",
+    "pytest-mock>=3.12",
+    "ruff>=0.5",
+]
+
+[project.scripts]
+obsidian-rag = "obsidian_rag.cli:main"
+
+[tool.setuptools.packages.find]
+where = ["."]
+include = ["obsidian_rag*"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+pythonpath = ["."]
+asyncio_mode = "auto"