…ard cursors

…in dbgen

… document chat query grammar

…indow

…t status

Review fixes for the signed chat file download flow and the extended
MCP tools:

- Exclude query strings from initial tracing span names so the signed
  download token (and other query credentials) never reaches tracing
  backends via the span name exported at span start.
- Stop echoing internal database error details from the unauthenticated
  signed download endpoint; log them instead.
- Truncate expires_at to whole seconds so the advertised expiry matches
  the JWT exp claim instead of overstating validity by up to a second.
- Make wait_secs a hard upper bound for coder_await_chat: timeout paths
  return the last status observed inside the wait window instead of
  issuing a post-deadline status fetch, and the tool description
  documents the timed_out semantics.
- Surface queued file-only prompts in queued_messages as an attachment
  summary instead of silently dropping them.
- Reject out-of-range wait_secs and limit values instead of silently
  clamping, matching coder_get_chat_messages validation, and fix the
  limit description that claimed newest-to-oldest order for forward
  (after_id) pagination.
- Add regression tests for redemption-time authorization: a revoked
  chat share and a suspended minting user must both invalidate an
  already-minted signed URL. Pin second-precision expires_at in the
  mint test and cover queued file-only prompts in the toolsdk tests.

…y credentials

Codex review fixes for PR #28233:

- coder_await_chat: drop the post-deadline fallback status fetch. When
  the initial status request outlives the wait window, the tool now
  returns the request error instead of running a fresh 15-second fetch
  from the caller context, which could stretch a wait_secs=1 call to
  roughly 16 seconds and report timed_out=false from a post-deadline
  observation. finalStatus now only reports states observed inside the
  window; all of its callers run after lastBusy is set. Regression test
  stalls every request and asserts the tool errors within the bound.

- coderd/tracing: regression test asserting no exported span surface
  (start-time name, final name, or completed-span attributes) carries a
  query-string credential. The vendored otel semconv v1.14 ServerRequest
  deliberately omits http.target, so completed spans do not leak the
  signed download token today; the test pins that invariant against
  future semconv upgrades.

…to 000572

Main gained 000571_pool_aware_chat_acquisition_index, so the PR merge
checkout contained two migrations with version 000571 and golang-migrate
failed to init in every CI job that touches the database (gen, lint,
sqlc-vet, offlinedocs, test-go-pg). The schema is unchanged; only the
version number moves past main's.

…alues

searchquery.Chats rejects unquoted values containing colons, so the
advertised diff_url:<url> form fails for any real URL unless quoted.
The coder_list_chats query description now says to quote values with
spaces or colons and shows a quoted diff_url example.