feat(memory): add branchable provider improvement system

[drewstone]

Summary\n\n- add official-client Mem0 hosted/OSS and Neo4j Agent Memory adapters plus Graphiti MCP support\n- add isolated branches, snapshots, forks, resume, private/team/shared policies, and ordered per-agent writes\n- add parallel multi-track configuration improvement with fresh-history comparison and atomic activation\n- add durable controller ownership, bounded recovery retries, retired-candidate cleanup, shared dollar limits, and complete cost attribution\n- harden provider scope rejection, exact deletion, delayed-write cleanup, timeout behavior, and late adapter release\n- document the 4.0.0 API and pre-4.0 run-directory migration boundary\n\n## Checks\n\n- 424/424 runnable tests passed across 104 files; 10 intentional skips; 0 failures\n- lint, TypeScript, build, and production dependency audit passed\n- clean tarball install imported all 5 public entry points, ran CLI version 4.0.0, and repacked\n- real SIGKILL and disk resume passed for both the multi-step experiment and direct benchmark paths\n- resumed runs cleared abandoned provider scopes before retry, left 0 active attempts, and left 0 provider records\n- independent read-only review confirmed the named isolation, timeout, cost, and recovery fixes; its late adapter leak finding is fixed with regression coverage\n\n## Limits\n\n- Mem0 and Neo4j compatibility is checked against official current SDK types and deterministic provider behavior tests\n- no live Mem0, Graphiti, or Neo4j credentials were available for a network run\n- deterministic benchmark scores prove execution and recovery behavior; they do not rank third-party memory systems

[tangletools]

✅ Auto-approved drewstone PR — c3cc7b4e

This PR was opened by the trusted drewstone account.
The full PR reviewer audit still runs separately and will publish findings if it detects issues.

_{tangletools · auto-approval · reason: drewstone_author · 2026-07-18T06:46:38Z}