D93 — Read-path Git freshness

Status: implemented (2026-07-24).

Decision. Every read-only MCP tool piggybacks SyncIn before serving a Git-synchronised KB. The existing git.in_window / CARTOGRAPHER_SYNC_IN_WINDOW freshness window limits both reads and writes to at most one fetch per KB per window. A pull that moves HEAD uses D90's reconciliation callback before the handler runs. A read-side rebase conflict is registered and marked degraded, while other sync failures are logged; either failure still serves the current local tree.

Rationale. Piggybacking avoids a per-KB background poller and its lifecycle/conflict-context complexity while bounding remote work with the existing window. Reads must stay available during a remote or rebase failure, so stale/degraded local content is preferable to turning an otherwise valid read into an MCP error.