grepai: fix index staleness, mandate usage, document config for new machines

Index was dead since 2026-04-19 (watcher not running). Fixes:
- Watcher restarted; scheduled task registered for login persistence
- Removed .md 0.6x penalty — markdown is primary content in this repo
- Added session-logs/ 1.3x, .claude/ 1.2x, /clients/ 1.1x relevance bonuses
- CLAUDE.md: grepai_search is now the first step for any context lookup
- OLLAMA.md: documents config overrides + watcher setup for new machines

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

.claude/CLAUDE.md

@@ -251,10 +251,13 @@ Tier 0 — **Ollama is the documentation engine.** Route all prose generation th
 
 ### GrepAI (Semantic Code Search)
 
-Use for intent-based search ("how does auth work"), exploring unfamiliar code, context recovery.
-- **MCP tool:** `grepai` server tools
-- **Agent:** `deep-explore` agent
-- **CLI:** `grepai search "query" --json --compact`
+**Use GrepAI first for any context lookup before reading files directly.** It indexes all session logs, skill files, and project docs with boosted relevance for `.claude/` and `session-logs/`.
+
+- **When to use:** "what did we do with X", "how does Y work", "find where Z is configured", context recovery, exploring unfamiliar code
+- **MCP tools:** `grepai_search` (primary), `grepai_trace_callers`, `grepai_trace_callees`
+- **Agent:** `deep-explore` (for multi-hop exploration)
+- **CLI:** `D:/claudetools/grepai.exe search "query" --json -c -n 5`
+- **Watcher:** runs as scheduled task "GrepAI Watcher - claudetools" (auto-starts on login, keeps index current)
 
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