feat: add consolidation accounting for workspace memory promotion

P0 implementation with four waves:

Wave 1: Dedup with accounting
- Add dedupeLongTermEntriesWithAccounting()
- Classify exact duplicate, identity duplicate, topic duplicate

Wave 2: Normalization with accounting
- Add normalizeWorkspaceMemoryWithAccounting()
- Chain redaction → migration → enforceLongTermLimitsWithAccounting

Wave 3: Promotion accounting integration
- Update accountPendingPromotions() to use new accounting API
- Add supersededKeys to classification
- Distinguish promoted / absorbed / superseded / rejected

Wave 4: Integration tests
- End-to-end tests covering full pipeline

Bug fixes:
- Fix active vs superseded boundary (superseded entries no longer block promotion)
- Remove unused rejected_duplicate_lower_quality type
- Defer pending journal safety cap (TODO added)

Tests: 135 passing (up from 115)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "opencode-working-memory",
-  "version": "1.2.3",
+  "version": "1.3.0",
   "description": "Three-layer memory architecture for OpenCode with workspace memory and hot session state",
   "type": "module",
   "main": "index.ts",