feat(session-query): ship full-text session search opt-in via openAt never

The shipped bundles keep ctx.sessionQuery mounted but set the new
session-query-sqlite `openAt: never` phase: searchSessions/searchEvents
fail with the typed SESSION_QUERY_SEARCH_DISABLED code before any request
normalization, node:sqlite is never imported or opened, and no source
observation or reconciliation runs. Every inherited exact read, filter,
and trace — session export descendants, subagent-fork Workspace
inheritance, title reads — keeps working, and the Web sidebar search
degrades to its designed local title/workspace matching. Enabling content
search is a one-line openAt override in a later patch layer; the web e2e
scaffold keeps it enabled as the assembled opt-in coverage.

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

@@ -16,7 +16,7 @@ All three surfaces (`current`, `shadowed`, and `log-only`) are searchable by def
 
 The service requires `ctx.sessions` and observes optional `ctx.sessionPersistence` dynamically. One serialized state machine compares source-qualified lightweight durable snapshot revisions, non-mutatingly inspects only new or changed logs, extracts shared semantic documents, reconciles changes transactionally, and runs the query. Session queries never invoke the persistence backend's crash-repairing `load()`; an owner attaching during inspection cannot mutate its log, and the stable-observation retry makes the result live-preferred. The TEMP live row still records persisted availability, and the durable base refreshes after that live owner detaches. Repeated queries and an unchanged same-store reopen perform no full durable-log inspection; switching stores, or observing new, changed, deleted, or externally load-repaired sources, reconciles on the next stable observation. Source or transaction failure commits nothing, and the next search retries.
 
-`openAt: startup` is the default: service activation imports `node:sqlite`, opens the handle, and fails before publication when the index is invalid. `openAt: first-search` publishes the service as ACTIVE without importing the SQLite module or opening a handle; the first concurrent searches share one readiness promise, and disposal before any search opens nothing. This mode supports compositions that need clean Node 22 startup output by deferring SQLite's experimental warning until the first actual search; it does not suppress a warning at that point. An invalid database likewise fails the first search instead of service activation.
+`openAt: startup` is the default: service activation imports `node:sqlite`, opens the handle, and fails before publication when the index is invalid. `openAt: first-search` publishes the service as ACTIVE without importing the SQLite module or opening a handle; the first concurrent searches share one readiness promise, and disposal before any search opens nothing. This mode supports compositions that need clean Node 22 startup output by deferring SQLite's experimental warning until the first actual search; it does not suppress a warning at that point. An invalid database likewise fails the first search instead of service activation. `openAt: never` turns full-text search off for the deployment: `searchSessions` and `searchEvents` fail with `SESSION_QUERY_SEARCH_DISABLED` before any request normalization, node:sqlite is never imported or opened, and no source observation or reconciliation runs, while every inherited exact read, filter, and trace on `ctx.sessionQuery` keeps working.
 
 Persisted FTS rows live in a dedicated derived database. Connection-local TEMP tables hold live rows, which shadow the durable base for the same session and reveal it when the live owner disappears. Unmounting persistence hides durable rows without discarding the cache; remounting reconciles it. Closing or reopening the database drops every live overlay while retaining persisted rows.
 
@@ -27,7 +27,7 @@ The database is disposable but reset is guarded: every recognized schema version
 | Key | Default | Contract |
 |---|---:|---|
 | `path` | required | Dedicated derived-index SQLite path; `:memory:` is supported. Missing filesystem paths are created owner-only on POSIX filesystems. |
-| `openAt` | `startup` | `startup` opens before service activation completes; `first-search` defers the SQLite module and handle until search. |
+| `openAt` | `startup` | `startup` opens before service activation completes; `first-search` defers the SQLite module and handle until search; `never` disables full-text search (typed `SESSION_QUERY_SEARCH_DISABLED` failures) while inherited reads stay available. |
 | `journalMode` | `wal` | `wal`, `delete`, `truncate`, or `persist`. |
 | `defaultLimit` | `20` | Page size when a request omits `limit`; at most `Number.MAX_SAFE_INTEGER - 1`. |
 | `maxLimit` | `100` | Largest accepted request page size; at most `Number.MAX_SAFE_INTEGER - 1`. |