docs: update deletion docs for tombstones, add changelog entries

- Rewrote DELETIONS.md to document inline tombstones (replacing legacy
  deletions.jsonl approach)
- Added tombstone feature entries to CHANGELOG.md under Unreleased
- Fixed duplicate 0.29.0 header in CHANGELOG.md
- Ran bd migrate-tombstones on beads repo (dogfooding)
- Closed bd-vw8 epic (all 12 dependencies complete)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- **Inline tombstones for soft-delete (bd-vw8)**
+  - Deleted issues now become tombstones with `status: "tombstone"` in `issues.jsonl`
+  - Full audit trail: `deleted_at`, `deleted_by`, `delete_reason`, `original_type`
+  - TTL-based expiration (default 30 days) with automatic pruning via `bd compact`
+  - Proper 3-way merge support: fresh tombstones win, expired tombstones allow resurrection
+  - Replaces the legacy `deletions.jsonl` manifest approach
+
+- **`bd migrate-tombstones` command (bd-8f9)**
+  - Converts legacy `deletions.jsonl` entries to inline tombstones
+  - Archives old file as `deletions.jsonl.migrated`
+  - Use `--dry-run` to preview changes
+
 ### Fixed
 
 - **`bd sync` race condition with daemon (bd-lw0x, bd-hxou)**
@@ -18,8 +32,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [0.29.0] - 2025-12-03
 
-## [0.29.0] - 2025-12-03
-
 ### Added
 
 - **`--estimate` / `-e` flag for `bd create` and `bd update` (GH #443)**