chore: mark M3.8.2 complete (3 cache metrics tests, 117 total)

tasks/INDEX.md

@@ -66,12 +66,12 @@ Legend: ⬜ not started · 🟡 in progress · ✅ done · ⛔ blocked
 | 5 | Skills | M4.x | 3 | 2 | 0 | 1 | ⬜ M4.3 |
 | 5.5 | Reference corpora | M3.6.x | 7 | 1 | 0 | 6 | ⬜ M3.6.8 |
 | 5.6 | Tool context | M3.7.x | 4 | 2 | 0 | 2 | ⬜ M3.7.6 |
-| 5.7 | Context optimization | M3.8.x | 4 | 1 | 0 | 3 | ⬜ M3.8.4 |
+| 5.7 | Context optimization | M3.8.x | 4 | 2 | 0 | 2 | ⬜ M3.8.4 |
 | 6 | Post-training | M5.x | 6 | 0 | 0 | 6 | ⬜ M5.6 |
 | 7 | agent-manager migration | M6.x | 6 | 0 | 0 | 6 | ⬜ M6.6 |
 | 8 | Source connectors | M7.x | 10 | 0 | 0 | 10 | ⬜ M7.10 |
 | 9 | Hybrid search | M8.x | 9 | 1 | 1 | 7 | ⬜ M8.9 |
-| | **Total** | | **76** | **61** | **0** | **15** | 7/13 green |
+| | **Total** | | **76** | **62** | **0** | **14** | 7/13 green |
 
 **Current status — 2025-01-28.** Completed phases M0.x, M1.x fully archived (16/16 tasks). **M2.1-6 ✅** (embeddings, CNPG, schema, pgvector, obsidian projector, rebuild). **M3.x ✅** (4/4). **M3.5.x ✅** (10/10 complete + archived). **M3.7.7-8 ✅** (failure diagnosis). **M4.1-2 ✅** (skill drafting + derived filter). **M3.6.1 ✅** (DocCorpusSource). **M3.6.3 ❌ retired** (Obsidian UI replaces CLI). **M3.6.7-8 ⬜ new** (ingest enrichment + deduplication). **M8.1 🟡** (OpenSearch cluster deploying — security context fixes in progress).
 
@@ -208,7 +208,7 @@ fidelity; only evidence chunks entering the prompt get optimized.
 | Task | Title | Size | Flags | Status |
 |---|---|---|---|---|
 | [M3.8.1](M3.8.1-context-optimizer.md) | Context optimizer pipeline (router + compressors + CCR) | L | — | ✅ COMPLETE |
-| M3.8.2 | CacheAligner integration with prompt builder | M | — | ⬜ |
+| [M3.8.2](M3.8.2-cache-aligner-headers.md) | CacheAligner integration with prompt builder | M | — | ✅ |
 | M3.8.3 | Compression benchmarks + tuning | M | — | ⬜ |
 | M3.8.4 | **M3.8 composition gate** | M | gate | ⬜ |