Third slice of the a2a_tools.py split (stacked on iter 4b). Owns the
two persistent-memory MCP tools:
* tool_commit_memory — write to /workspaces/:id/memories with RBAC
+ GLOBAL-scope tier-zero enforcement
* tool_recall_memory — search /workspaces/:id/memories with RBAC
a2a_tools.py shrinks from 609 → 508 LOC (−101). Both handlers depend
ONLY on a2a_tools_rbac (iter 4a), a2a_client, and the platform's
/memories endpoint — no entanglement with delegation or messaging.
Side-effects of the layered architecture: a2a_tools_memory's import
contract is "depends on a2a_tools_rbac, never on a2a_tools" — the
kitchen-sink module is for back-compat re-exports only. A test pins
this so a future refactor that re-introduces `from a2a_tools import …`
fails in CI.
Tests:
* 49 patch sites in TestToolCommitMemory + TestToolRecallMemory
retargeted from `a2a_tools.{_check_memory_*, _is_root_workspace,
httpx.AsyncClient}` to `a2a_tools_memory.…` because the call sites
moved.
* test_a2a_tools_memory.py adds 4 new tests (alias drift gate +
import-contract + a2a_tools-side re-export).
117 tests total (77 impl + 28 rbac + 8 delegation + 4 memory), all green.
Refs RFC #2873.
