Refactor: project review cleanup — dead code, DRY, data integrity

[shoom1]

Summary

Address quick-win and medium-effort items from March 2026 project review:

• Dead code removal: Remove unused constants from config.py, dead functions from logging.py, dead generate_tool_summary from ADK, redundant is_recursive branch in glob_tool.py, stale resolvers.py reference from CLAUDE.md
• DRY fixes: Extract _find_document_in_kbs KB lookup helper, extract test context fixtures (task_store_ctx, memory_store_ctx, plan_store_ctx), consolidate 3 settings mutation patterns into update_setting() method
• Coupling reduction: Add public set_input_callback()/clear_input_callback() API to BaseWorkflowManager, cache ripgrep availability check with lru_cache
• Data integrity: Swap vector store save order (mappings before FAISS index) for crash safety, reorder ingest_document() to add embeddings before updating in-memory state

21 files changed, -30 lines net. 947 tests pass (9 new).

Test Plan

• Full test suite: 947 passed, 6 skipped, 27 xfailed
• Import verification: from agentic_cli import BaseCLIApp, BaseSettings works
• New tests for update_setting(), _find_document_in_kbs, input callback API, ripgrep cache