feat(coder,server): audit engine — session audit, guideline compliance, user correction tracking

Implements audit-harness-inspired session lifecycle: audit session
creation/end/recover/report-daily with JSONL buffer and graded context
recovery (L0-L4). Guideline service for behavioral compliance rules
(condition/action model with criticality). Correction service for
persistent user correction tracking across agent sessions.

8 supporting skills: audit-start/end/report-daily/recover + command
variants for slash-command integration.

data/skills/boocode/command-start/SKILL.md

@@ -0,0 +1,72 @@
+---
+name: command-start
+description: Create an audit session with context recovery before starting work. Use when beginning a new task, analysis, or code modification — establishes a session for tracking tool usage, user corrections, and decisions. Examples: "start", "begin session", "start work", "/start 'migrate database schema'".
+allowed-tools:
+  - Read
+  - Glob
+  - Grep
+  - Bash
+  - Write
+---
+
+# /start — Audit Session Start + Context Recovery
+
+## Trigger
+
+```
+/start "task description"
+```
+
+## Why
+
+Every task should run in an audit session. Without one:
+- Tool-use data goes to unnamed sessions with no task context
+- `/end` can't run integrity checks
+- Daily reports miss task descriptions
+
+## Steps
+
+### 1. Create session
+
+Generate `session_id = adhoc_YYYYMMDD_HHMM`, create `.boo/runs/{session_id}/`, write `session.json`:
+
+```json
+{
+  "session_id": "adhoc_20260320_1400",
+  "task": "task description",
+  "start_time": "ISO 8601",
+  "status": "in_progress",
+  "expected_record_types": ["data", "change", "conversation"]
+}
+```
+
+Write session_id to `.boo/runs/.current_session` (the Stop hook reads this for buffer archiving).
+
+### 2. Context recovery (L0 + L2)
+
+**L0 — Index summary**: read `.boo/runs/index.json`, last 5 entries.
+
+**L2 — User corrections (critical)**: scan all `audit_trail.jsonl` and `audit_pending.jsonl` for `user_correction` records — these must be restored first to avoid repeating mistakes.
+
+**Check for unfinished sessions**: scan `.boo/runs/adhoc_*/session.json` for `status: "in_progress"`. If found, prompt the user to continue the old session instead.
+
+### 3. Output summary
+
+```
+Session created: adhoc_20260320_1400
+Task: {description}
+
+Context recovery:
+  Recent activity: {last 3 completed tasks}
+  User corrections (must follow): {all user_correction records}
+  Unresolved issues: {open anomalies/alerts}
+  Today's priorities: {from morning review}
+
+All [AUDIT] blocks use batch_id = {session_id}
+```
+
+### 4. Notes
+
+- If `.boo/runs/` doesn't exist, create it and skip recovery
+- If `.current_session` already points to an in_progress session, prompt before creating a new one
+- The session_id stays constant for the whole session — all [AUDIT] blocks share it