fix(session): add semantic crash checkpoints

packages/session-persistence/session-persistence-sqlite/README.md

@@ -39,7 +39,7 @@ Like the JSONL backend, the plugin also installs the `session/event` → buffer
 
 #### What the model sees
 
-SQLite storage contributes no live prompt or schema. Loading restores the same surface history as JSONL and preserves prior headers for reconstruction; the new loop composes its current envelope. Each unanswered call in interrupted rows is balanced with the exact error text `Tool call interrupted by a crash; no result was recorded.` Row metadata and raw chunks are not messages.
+SQLite storage contributes no live prompt or schema. Loading restores the same surface history as JSONL and preserves prior headers for reconstruction; the new loop composes its current envelope. Recovery balances an assistant request without a durable call with `TOOL_NOT_STARTED`; a durable call without a result becomes `TOOL_OUTCOME_UNKNOWN`, which tells the model to retry only read-only or idempotent work and to verify possible side effects or ask the user. Row metadata and raw chunks are not messages.
 
 #### Token effect
 

packages/session-persistence/session-persistence-sqlite/src/schema.ts

@@ -166,8 +166,8 @@ export function scanRows(rows: readonly EventRow[]): { preserved: SessionEvent[]
     }
   })
 
-  // The last index that is a valid `turn/end` — the last fully-committed
-  // boundary (the loop flushes only at turn/end).
+  // The last index that is a valid `turn/end` — holes through a closed turn
+  // are always committed corruption.
   let lastTurnEnd = -1
   for (let i = parsed.length - 1; i >= 0; i--) {
     if (parsed[i]?.ok && rows[i]?.type === 'turn/end') { lastTurnEnd = i; break }