feat: auto-generate session titles via the managed chat_title tool - #2351

Drop the automatic wiring on both engines: the v1 (TUI) first-prompt
trigger and the v2 easy-title event watcher. SessionTitleService's
generateTitle() stays as the single on-demand entry point behind the
auto-title flag, backing the kap-server title/generate route. The
changeset goes away too: with no shipped consumer, the remaining
surface is not user-perceivable.

# Conflicts:
#	packages/agent-core-v2/test/session/sessionMetadata/sessionMetadata.test.ts

- persist titleSource (prompt/generated/custom); skip auto-generation over
  an already-generated title unless forced, and never over a custom one
- plumb the force option from the core through klient and node-sdk to the
  REST title/generate endpoint
- drop the title write-back when the session scope was superseded
  mid-flight, and retry once with a force-refreshed token on a 401
- stop closing sessions a concurrent public resume has handed out in the
  temporary resume paths (generateSessionTitle, renameSession)
- accept session.meta.updated patches without lastPrompt in klient event
  validation, and emit exactly one metadata event per applied title
- remove the retired prompts field heal and drop the changeset (the
  behavior is only perceivable on the experimental v2 engine)

# Conflicts:
#	packages/agent-core-v2/docs/state-manifest.d.ts
#	packages/agent-core-v2/test/workspace/workspaceHandler/workspaceHandler.test.ts
#	packages/node-sdk/src/sdk-rpc-client-v2.ts

…dler

The session title service must not depend on the Workspace-tier handler
registry. The handler now seeds each session scope with an abort signal,
fires it synchronously when a close begins, and the title service carries
the signal on its request, drops the write-back once aborted, and drains
an in-flight generation through the onWillCloseSession hook.

A v1 rename spreads the original state.json document, so an explicit
isCustomTitle: true can travel with a stale titleKind. The explicit
marker now wins on load, and every persist double-writes the derived
isCustomTitle so released v1 builds keep recognizing the custom title.

The temporary resume/rename/close paths and the public lifecycle
operations now share a per-session queue, so a public resume can never
receive a handle whose cleanup close is already in flight. Session
summaries carry the canonical title state, letting the TUI skip title
generation for sessions whose title was already generated or customized
instead of re-asking after every turn.

A close/archive is now tracked in a closing registry from its first
synchronous step until disposal: get/list hide the closing session and
resume waits the close out instead of returning the doomed handle, and
fork waits out an in-flight source close. The title service tracks the
whole generateTitle call as the unit the close hook drains, and the
generated-title write re-checks the lifetime signal inside the serialized
metadata update so an abort landing while the update is queued still
vetoes the write-back.

readSummary and the read-model mirror carry titleKind, so listSessions
reports the same canonical title state as a resumed session's summary.

…sion index

The listed-session titleKind had no consumer: the TUI's title-generation
gate seeds from the resumed summary, which reads the live metadata
document, and the kap-server REST wire never carried the field. Removing
the projection also retires the read-model summary version stamp (the
remaining shape is fully field-checkable) and the duplicate title-kind
derivation that had to stay in lockstep with sessionMetadata. The klient
list contract and the node-sdk list mapper drop the field with it; the
resumed/live summary still reports the canonical title state.

…essageLegacy

mergeContextTranscriptWithLive had a single caller; move the logic into
messageLegacyService as the private mergeLiveTail and drop the export.

# Conflicts:
#	packages/agent-core-v2/docs/state-manifest.d.ts
#	packages/agent-core-v2/scripts/check-domain-layers.mjs
#	packages/agent-core-v2/src/session/sessionMetadata/sessionMetadataService.ts
#	packages/agent-core-v2/src/workspace/sessionLifecycle/sessionLifecycleService.ts
#	packages/node-sdk/src/sdk-rpc-client-v2.ts

…ifecycle

Auto title no longer consumes close-awareness, so the machinery goes
back to the simple forms: close/archive run straight through, resume
no longer waits out an in-flight close, create/fork drop their target
reservation, and a cold archive is a no-op again. Reverts the behavior
of e7c397a and cd1cea0 on top of the sessionLifecycle rename.

Signed-off-by: 7Sageer <sag77r@hotmail.com>

…title test

The main merge reduced #/kosong/model/hostRequestHeaders to the pure
port contract; define the test's headers as a plain value matching it
and tidy the SDK test import grouping.

…quest input

Keep the capability only: the engine-side title generation service, the
POST /sessions/{id}/title/generate route, and the SDK generateSessionTitle
method stay; the TUI no longer requests a title on prompt accept or on
session attach. The changeset now covers the SDK capability instead of a
CLI-facing auto title.

Signed-off-by: 7Sageer <sag77r@hotmail.com>

ISessionTitleService.generateTitle and the metadata write-back take an
optional force flag that bypasses the custom/generated guards, so an
explicit user request (the desktop/web rename field's Gen Title action)
can overwrite any current title; the applied title is marked generated.
Forced calls skip the in-flight coalescing, and a forced write is plain
last-writer-wins.

kap-server's POST /sessions/{id}/title/generate accepts an optional
{ "force": true } body; klient and the node-sdk plumb the option through
(GenerateSessionTitleInput.force).

Also renumber SESSION_TITLE_UNAVAILABLE to 40923: main assigned 40922 to
PAGE_TOKEN_MISMATCH after this branch forked.

…ation

generateTitle gains a source option alongside force:

- user_prompts (default): the existing first-prompts window, unchanged.
- first_turn: the opening user prompt paired with the first turn's final
  assistant text — strict, so a caller asking before the first reply lands
  simply gets unavailable and can retry at the next turn boundary.
- digest: first prompt + latest prompt + the latest turn's final assistant
  text, tolerating a compacted window by using whatever segments survive;
  meant for explicit regeneration on multi-turn sessions.

Assistant segments keep only natural-language text parts (tool calls,
thinking, and media never contribute) and pass through the shared metadata
sanitizer, which redacts secrets and long base64-looking runs; each
segment is capped (user 300, assistant 600/400) so the composed
chat_content stays within the 1000-char budget. The kap-server route,
klient contract, and node-sdk plumb the option through. Excerpt extraction
is covered against the real context memory (loop-event folding), and the
REST surface gains a digest composition case.

# Conflicts:
#	packages/agent-core-v2/src/agent/rpc/prompt-metadata.ts
#	packages/agent-core-v2/src/index.ts
#	packages/agent-core-v2/src/session/sessionMetadata/sessionMetadataService.ts
#	packages/agent-core-v2/src/workspace/sessionLifecycle/sessionLifecycleService.ts
#	packages/agent-core-v2/test/agent/prompt/promptMetadataText.test.ts
#	packages/agent-core-v2/test/app/sessionIndex/sessionIndex.test.ts
#	packages/agent-core-v2/test/workspace/sessionLifecycle/sessionLifecycle.test.ts
#	packages/kap-server/src/protocol/error-codes.ts
#	packages/kap-server/src/routes/sessions.ts
#	packages/klient/src/contract/index.ts
#	packages/klient/src/transports/memory/serviceRegistry.ts
#	packages/klient/test/contract-parity.ts
#	packages/node-sdk/src/sdk-rpc-client-v2.ts
#	packages/node-sdk/test/sdk-rpc-client-v2.test.ts
#	packages/node-sdk/test/v1-v2-parity.test.ts

Snake-case id matching search_worker / persistence_minidb_readmodel; env
KIMI_CODE_EXPERIMENTAL_AUTO_SESSION_TITLE.

The main-merge commit captured pre-fix snapshots of four files; the
actual resolutions only lived in my working tree: the LifecycleScope
import move to #/app/scopes, the titleKind port of
applyPromptMetadataUpdate, the Promise<void> pinning of the metadata
update queue, and the reloadSession runSessionAccess closure.

Generation now reports unavailable with the flag off, so the two
title-generation harnesses opt in through the written config's
[experimental] section.