fix(persistence): tighten crash repair and dispose semantics

packages/session-persistence-sqlite/README.md

@@ -14,7 +14,7 @@ The repo targets Node ≥ 24 (the root `engines` field), which includes the stab
 
 - **Append = a transaction.** `append` runs `BEGIN`/`COMMIT` around the batch: it materializes the `sessions` row (if still lazy) and INSERTs every event, asserting the contiguous-seq contract first (the first event's `seq` must equal the stored next-seq). A mid-batch failure (a UNIQUE violation on a duplicated seq) rolls back entirely, so the stored log and the in-memory cursor stay consistent. (`load()` already balanced the stored log, so `append` never has to repair a crash tail.)
 - **Lazy materialization.** `create()` records intent in memory only — no row is written until the first `append`. A created-but-never-appended session has no `sessions` row, so it is absent from `has()`/`list()` (which report exactly the sessions that have a row).
-- **Interrupted-turn close on load.** `load()` reads every stored event ordered by `seq` and finds the longest seq-contiguous, parseable prefix — INCLUDING the real events of an interrupted final turn after the last `turn/end` (the loop only flushes at `turn/end`, so a process killed mid-turn leaves real, fully-written rows past it). A single turn can be huge in a long-horizon task, so those events are **preserved, never truncated**: `load()` CLOSES the orphaned turn by durably appending the minimal synthetic boundary events (a `step/end` if a step was open, then a `turn/end` carrying `{ kind: 'interrupted' }`), inside one transaction that also DELETEs any never-fully-written torn tail row. `load()` is therefore mutating — after it the stored rows are balanced and the cursor is truthful, so the next `append` continues cleanly. The boundary (last `turn/end`, torn-tail detection) is computed from the `seq`/`type` columns so a malformed `data` in a torn tail row is never parsed (discarded, not unloadable). A parse error or `seq` gap inside the committed region (at or before the last real `turn/end`) makes the session unloadable. A session whose only turn never closed keeps its metadata row and stays present in `has()`/`list()` — the same as the JSONL backend, whose file likewise survives a first append that never reached `turn/end`.
+- **Interrupted-turn close on load.** `load()` reads every stored event ordered by `seq` and finds the longest seq-contiguous, parseable prefix — INCLUDING the real events of an interrupted final turn after the last `turn/end` (the loop only flushes at `turn/end`, so a process killed mid-turn leaves real, fully-written rows past it). A single turn can be huge in a long-horizon task, so those events are **preserved, never truncated**: `load()` CLOSES the orphaned turn by durably appending the minimal synthetic boundary events (an error `tool/result` for every assistant tool call left unanswered, a `step/end` if a step was open, then a `turn/end` carrying `{ kind: 'interrupted' }`), inside one transaction that also DELETEs any never-fully-written torn tail row. `load()` is therefore mutating — after it the stored rows are balanced and the cursor is truthful, so the next `append` continues cleanly. The boundary (last `turn/end`, torn-tail detection) is computed from the `seq`/`type` columns so a malformed `data` in a torn tail row is never parsed (discarded, not unloadable). A parse error or `seq` gap inside the committed region (at or before the last real `turn/end`) makes the session unloadable. A session whose only turn never closed keeps its metadata row and stays present in `has()`/`list()` — the same as the JSONL backend, whose file likewise survives a first append that never reached `turn/end`.
 
 ## Configuration (schemastery)