Merge remote-tracking branch 'origin/master' into xtr/identified-immutable-messages

# Conflicts:
#	.agents/notes/implemented/feature/2026-07-21-cross-session-references.i18n.yaml
#	packages/context/session-reference/README.i18n.yaml
#	packages/context/session-reference/README.md
#	packages/context/session-reference/README.zh.md
#	packages/context/session-reference/src/index.ts

.agents/notes/implemented/feature/2026-07-21-cross-session-references.md

@@ -14,7 +14,7 @@ TUI users need to bring relevant work from another conversation into one new mes
 
 `dsh-session:<base64url(JSON.stringify(sessionId))>` is the canonical host-independent identifier. JSON string encoding precedes base64url so quotes, slashes, backslashes, Unicode, newlines, and every other JavaScript string value round-trip without delimiter ambiguity. TUI renders that URI inside `@[label](uri)`; text-only clients may use the same inline mention. Explicit Markdown mentions reject malformed URIs. Bare text becomes a reference only for a non-empty base64url-shaped payload, whose decode must still be canonical; empty or punctuation-only uses remain ordinary discussion text.
 
-The service uses `ctx.sessionQuery.readSurface(sessionId)`, which loads one live-preferred corpus observation, folds it with the session package's canonical surface algorithm, and returns a detached header, capture seq, and current nodes. FTS is not a dependency: v1 discovery filters only id and cwd, and future title/body search can replace the candidate layer without changing reference identity or preparation.
+The service uses `ctx.sessionQuery.readSurface(sessionId)`, which loads one live-preferred corpus observation, folds it with the session package's canonical surface algorithm, and returns a detached header, capture seq, and current nodes. FTS is not a dependency: discovery matches id, cwd, or the latest folded title, while message bodies remain outside the candidate layer. Non-empty queries batch title observations across the visible corpus with bounded persisted-log concurrency and cancellation; a dedicated title index can replace that discovery path without changing reference identity or preparation.
 
 ## Snapshot and projection
 
@@ -32,7 +32,7 @@ Reference preparation is not a new steering protocol and does not create a turn
 
 ## Host adapters
 
-TUI combines session candidates with the existing `@` file provider. Each candidate displays the latest folded session title and falls back to the session id; lookup follows the editor's cancellation signal, and session id, cwd, and mention labels escape external terminal controls while the canonical URI retains the original id. TUI prepares only submissions containing structured mentions, disables duplicate submit while awaiting snapshots, restores failed input, renders the readable direct content as the user message, and renders session-reference source metadata as a compact source list instead of exposing the complete JSON in the terminal.
+TUI combines session candidates with the existing `@` file provider. Candidate lookup matches case-insensitive substrings of the session id, cwd, or latest folded title, displays that title, and falls back to the session id when a title observation is absent or fails. Lookup follows the editor's cancellation signal, and session id, cwd, and mention labels escape external terminal controls while the canonical URI retains the original id. TUI prepares only submissions containing structured mentions, disables duplicate submit while awaiting snapshots, restores failed input, renders the readable direct content as the user message, and renders session-reference source metadata as a compact source list instead of exposing the complete JSON in the terminal.
 
 The [automation-only ACP transport](../simplification/2026-07-23-acp-automation-only-protocol.md) deliberately does not mount session-query or session-reference services.
 
@@ -53,7 +53,7 @@ Each of at most three references is independently capped at 65,536 UTF-8 bytes b
 
 ## Verification
 
-Unit and integration coverage pins URI round-trips and text-boundary punctuation, explicit malformed references, title-aware candidate ranking, terminal-control escaping, projection exclusions, non-recursive snapshot projection, backend-independent compact checkpoints, tag-safe framing, deduplication, self-reference, count limits, all-or-nothing reads, prompt cancellation against a non-settling storage read, independent per-source byte retention, prompt blocking, admission-time staging, send/steer placement, title isolation, missing capability, and compact TUI replay. A keyless TUI snapshot runs the real agent loop: the source surface replaces old user/assistant history with a compact checkpoint, the target submits a mention, and the captured model request contains a sourced snapshot message followed by the readable current prompt, without either shadowed string.
+Unit and integration coverage pins URI round-trips and text-boundary punctuation, explicit malformed references, id/cwd/title candidate matching and ranking, failed title-observation fallback, candidate cancellation, terminal-control escaping, projection exclusions, non-recursive snapshot projection, backend-independent compact checkpoints, tag-safe framing, deduplication, self-reference, count limits, all-or-nothing reads, prompt cancellation against a non-settling storage read, independent per-source byte retention, prompt blocking, admission-time staging, send/steer placement, title isolation, missing capability, and compact TUI replay. One keyless terminal snapshot types a title-only substring against an opaque session id and pins the rendered candidate. Another keyless TUI snapshot runs the real agent loop: the source surface replaces old user/assistant history with a compact checkpoint, the target submits a mention, and the captured model request contains a sourced snapshot message followed by the readable current prompt, without either shadowed string.
 
 ## Consequences