feat: Load keywords from project-local .claude/keywords.json

Replace hardcoded MirrorBot-specific keywords with project-local configuration,
making the context router usable across any codebase without script modification.

Changes:
- Add load_project_config() to load keywords, co_activation, and pinned files
- Config lookup: .claude/keywords.json > ~/.claude/keywords.json > empty defaults
- Update docs_root to prefer project-local .claude/ directory
- Remove ~220 lines of hardcoded keywords from context-router-v2.py
- Add templates/keywords.json.example template
- Add working example to examples/small-project/
- Update all documentation to reference JSON config

This change was motivated by the experience documented at:
https://hitchcock.dev/i-spent-3-hours-fixing-a-15-minute-setup/

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: togabrennan

CHANGELOG.md

@@ -9,7 +9,25 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-*Nothing yet - stay tuned for v1.2!*
+### Added
+- **Project-local keyword configuration**: Keywords, co-activation, and pinned files now load from `.claude/keywords.json` instead of being hardcoded in the script
+  - Config lookup order: project `.claude/keywords.json` > global `~/.claude/keywords.json` > empty defaults
+  - Added `load_project_config()` function in `context-router-v2.py`
+  - Added `templates/keywords.json.example` template file
+  - Added example `keywords.json` to small-project example
+
+### Changed
+- **docs_root resolution**: Now prefers project-local `.claude/` directory over global `~/.claude/`
+  - Priority: `CONTEXT_DOCS_ROOT` env > project `.claude/` > global `~/.claude/`
+- Updated all documentation to reference `.claude/keywords.json` instead of editing the Python script
+  - `CUSTOMIZATION.md`: Complete rewrite for JSON config
+  - `README.md`: Updated Quick Start step 5 and added Project Configuration section
+  - `SETUP.md`: Added "Create Keywords Config" step
+  - `docs/guides/getting-started.md`: Updated customization instructions
+  - `docs/concepts/attention-decay.md`: Updated pinned files and troubleshooting sections
+
+### Removed
+- Hardcoded MirrorBot-specific keywords, co-activation rules, and pinned files from `context-router-v2.py` (~220 lines)
 
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