Add best-practices library, knowledge distillation pipeline settings, and first session log

- best-practices/: 11 topic files + INDEX.md extracted from cluster-bootstrap
  and custom-claude-skills (validation, k8s, helm, ansible, secrets, debugging, etc.)
- settings.yaml: pipeline config (log retention, tracked projects, max logs per run)
- CLAUDE.md: updated with best-practices loading and pipeline documentation
- memory/log/: first session log demonstrating the format

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

CLAUDE.md

@@ -15,9 +15,9 @@
    Scan the directories at runtime so the list is always current. Include a brief description if the project has a CLAUDE.md or README.md you can glean one from.
 
 2. Based on the user's choice:
-   - **Existing project**: `cd` into the directory, read all `.md` files, and read `~/dev/claude/secrets/` (read-only reference — review every file to refresh context). Ask clarifying questions if anything is unclear or incomplete, and note context in MEMORY.md.
+   - **Existing project**: `cd` into the directory, read all `.md` files, and read `~/dev/claude/secrets/` (read-only reference — review every file to refresh context). Then read the [Best Practices Index](best-practices/INDEX.md) and load any topic files relevant to the selected project's technology stack. Ask clarifying questions if anything is unclear or incomplete, and note context in MEMORY.md.
    - **No project right now**: Do nothing further — just respond normally.
-   - **New project!**: Follow the "New Projects" section below. Also read `~/dev/claude/secrets/` as above.
+   - **New project!**: Follow the "New Projects" section below. Also read `~/dev/claude/secrets/` as above. Read the [Best Practices Index](best-practices/INDEX.md) and load topic files relevant to the new project's technology stack.
 
 ## Secrets (`~/dev/claude/secrets/`)
 
@@ -110,6 +110,27 @@ Human-readable project documentation:
 - Milestone table with status
 - Scripts section listing every script with purpose and usage
 
+## Knowledge Distillation Pipeline
+
+Three skills form a continuous learning pipeline across projects:
+
+1. **`/log`** — Run at end of session. Captures decisions, gotchas, open questions to `memory/log/YYYY-MM-DD.<HHMMSS>.md` in the current project. Also prunes old reflected logs.
+2. **`/reflect-logs`** — Run periodically. Processes unprocessed session logs into topic memory files (`memory/gotchas-*.md`, `memory/process-lessons.md`, etc.). Flags stale entries. Tracks state in `.reflection-state.json`.
+3. **`/distill-best-practices`** — Run from any project. Reads changed memory files across all tracked projects and proposes updates to `claude-foundations/best-practices/`. Tracks state in `best-practices/.distill-state.json`.
+
+### State Files
+- **`.reflection-state.json`** — Per-project, tracks which logs have been reflected on (md5 hashes of log file content)
+- **`best-practices/.distill-state.json`** — In claude-foundations, tracks git SHAs per project at time of last distillation
+- **`settings.yaml`** — In claude-foundations, configures log retention (default 7 days), max logs per reflection run, and tracked project list
+
+### Log Format
+Session logs use structured markdown with parseable section headers: Summary, Decisions, Gotchas Discovered (tagged with `[topic]` for routing), Open Questions, Key Context, Process Notes. Empty sections are omitted.
+
+### Pruning
+- Reflected logs older than `log.retention_days` (default: 7) are automatically deleted by `/log`
+- Unreflected logs older than `log.warn_unreflected_days` (default: 14) trigger a warning instead of deletion
+- `/reflect-logs` flags stale memory entries (version-specific bugs that have been fixed, manual processes that have been automated)
+
 ## Milestones
 
 Break projects into numbered milestones (M1, M2, ...). Every milestone completion MUST include: