Merge remote-tracking branch 'origin/master' into codex/trim-ai-prose

# Conflicts:
#	docs/AGENTS.md
#	docs/config-catalog.md
#	packages/bash/bash-sandbox/src/index.ts
#	packages/bash/bash/src/session-mode.ts
#	packages/bash/tool-bash/README.md
#	packages/code-runtime/code-runtime-worker/README.md
#	packages/compact/compact/src/index.ts
#	packages/core/agent-core/README.md
#	packages/hooks/hooks-claude/src/config.ts
#	packages/hooks/hooks-claude/src/index.ts
#	packages/hooks/hooks-codex/src/config.ts
#	packages/hooks/hooks-codex/src/index.ts
#	packages/llm/llm/README.md
#	packages/session-persistence/session-persistence-jsonl/README.md
#	packages/session-persistence/session-persistence/README.md
#	packages/skill/skill-local/README.md
#	packages/support/acp-snapshot/README.md
#	packages/support/invariants/src/index.ts
#	packages/ui/acp/README.md
#	packages/ui/jsonrpc-agent/README.md
#	packages/ui/jsonrpc/README.md
#	packages/ui/permission/README.md
#	packages/ui/user-approval/README.md
#	packages/ui/user-interaction/README.md
#	packages/web/web-search-deepseek/README.md

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

@@ -21,12 +21,26 @@ The JSONL durable session-persistence backend — a concrete `SessionPersistence
 
 ## Durability and crash semantics
 
-- **Lazy materialization.** `create(meta)` writes nothing; the `.jsonl` (header + first batch) is written atomically (temp-write + `fsync` + rename) on the first `append`. A created-but-never-appended session leaves nothing on disk and is absent from `list`.
+- **Lazy materialization.** `create(meta)` writes nothing; on the first `append`, the backend writes and `fsync`s a temporary file, publishes it without overwrite via a hard link, then `fsync`s the directory. A created-but-never-appended session leaves nothing on disk and is absent from `list`.
 - **Append-only.** Committed events (at or below a flushed `turn/end`) are never rewritten. Subsequent appends are line appends at EOF + `fsync`.
 - **Crash recovery — close, don't truncate.** `load` preserves valid events from an interrupted final turn, appends the synthetic tool, step, and turn closers required by the shared [persistence contract](../../../docs/rfc/implemented/architecture/2026-06-14-session-persistence.md), and removes only an incomplete final line.
 - **Contiguous-seq.** `load` rejects a mid-log parse error or `seq` gap (unloadable); `append` rejects a batch whose first `seq` does not continue the stored log, and rejects non-JSON-serializable `event.data` naming the offending event type.
-- **Format version.** Only the current `SESSION_FORMAT_VERSION` (v0) is supported; `load` rejects any other version. While the harness is unreleased the on-disk format is pre-release/unstable: a breaking format change is absorbed at v0 (no bump until the first tagged release) and non-current logs are rejected — there is no migration (no persisted user data to preserve).
 
 ## Write path
 
 The plugin buffers frozen session events and drains them on flush or disposal. A per-session cursor prevents resumed sessions from re-appending stored events, and live sessions are seeded when the plugin loads. Operations for one session are serialized; disposal waits for initialization and the final drain so no write lands after teardown.
+
+## Model Experience
+
+### Resumed conversation history
+
+**What the model sees**: JSONL storage contributes no live prompt or schema. Loading restores stored surface history and preserves prior request headers for reconstruction; the new loop composes its current envelope. Each unanswered call in an interrupted tail is balanced with the exact error text `Tool call interrupted by a crash; no result was recorded.` Raw `assistant/chunk` records do not duplicate messages.
+
+**Token effect**: Zero live-request tokens. A resumed agent pays for retained history and its current envelope, plus the quoted repair result for each interrupted call.
+
+## Known Limitations and Deferred Work
+
+- **Only the current `SESSION_FORMAT_VERSION` (v0) loads** — the on-disk format is pre-release/unstable: a breaking format change is absorbed at v0 and non-current logs are rejected; there is no migration.
+- **Nothing deletes session files** — logs accumulate under `root` until removed externally (the seam has no deletion surface).
+- **Single-process assumption** — per-session serialization and the write cursor live in this process; two processes appending to the same `root` are not coordinated.
+- **Initial materialization requires hard-link support** — first append uses `link()` so same-id races fail instead of overwriting a committed log; a filesystem that cannot create hard links cannot host this backend.