feat: finalize package presence branch and docs alignment

CHANGELOG.md

@@ -10,7 +10,20 @@ ______________________________________________________________________
 
 ### Added
 
-- Nothing yet.
+- Tier 3 core session memory implementation:
+  - new `src/tai/session_store.py` persistent ChromaDB store
+  - `--session-memory` option on `tai run`
+  - prior-session retrieval injected into analysis/follow-up prompts
+  - final response indexing at session end
+- Planner enhancements for broader service detection:
+  - generic service candidate extraction from free text
+  - package presence probes in plans (`rpm -q` and `dpkg-query -W`)
+- SSH read-only allowlist expanded to permit package presence commands (`rpm`, `dpkg-query`)
+- Session memory tests in `tests/test_session_store.py`
+
+### Changed
+
+- Documentation alignment updates in README and ROADMAP to reflect implemented session memory and package-presence capabilities.
 
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