Add command documentation and improve daemon UX

- Added human-readable uptime formatting (51m 59s vs 3119.4 seconds)
- Fixed daemon stop race condition with SIGKILL
- Added markdown docs for 19 commands: blocked, comments, compact, daemon,
  delete, dep, epic, export, import, label, list, quickstart, rename-prefix,
  renumber, reopen, repos, restore, stale, sync
- Closed: bd-159, bd-152, bd-168
- Deleted test issues: bd-144, bd-145

Amp-Thread-ID: https://ampcode.com/threads/T-9f7c3fed-62de-4bcd-a059-8c1b77cdb841
Co-authored-by: Amp <amp@ampcode.com>

commands/compact.md

@@ -0,0 +1,31 @@
+---
+description: Compact old closed issues using semantic summarization
+argument-hint: [--all] [--id issue-id] [--dry-run]
+---
+
+Reduce database size by summarizing closed issues no longer actively referenced.
+
+## Compaction Tiers
+
+- **Tier 1**: Semantic compression (30+ days closed, ~70% size reduction)
+- **Tier 2**: Ultra compression (90+ days closed, ~95% size reduction)
+
+## Usage
+
+- **Preview candidates**: `bd compact --dry-run`
+- **Compact all eligible**: `bd compact --all`
+- **Compact specific issue**: `bd compact --id bd-42`
+- **Force compact**: `bd compact --id bd-42 --force` (bypass age checks)
+- **View statistics**: `bd compact --stats`
+
+## Options
+
+- **--tier**: Choose compaction tier (1 or 2, default: 1)
+- **--workers**: Parallel workers (default: 5)
+- **--batch-size**: Issues per batch (default: 10)
+
+## Important
+
+This is **permanent graceful decay** - original content is discarded. Use `bd restore <id>` to view full history from git if needed.
+
+Useful for long-running projects to keep database size manageable.