perf(server): bound run reads in authentication and conversation recovery (#17663)

Read compact run identity during authentication and compact turn state during conversation recovery. Preserve fresh checks, durable steering and reply evidence, locking, and complete stored payloads.

Validate 184 targeted PostgreSQL and lifecycle tests, workspace typecheck, server build, full CI, and Apex 5/5.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

doc/DATABASE.md

@@ -49,12 +49,24 @@ and leaves all existing cases passive. Source identities are not grants.
 
 ### Task query performance
 
+Agent request authentication uses a compact run-identity read. It omits saved
+execution payloads, results, and log excerpts from the query response. The read
+still locks the task before the run and reconciles pending steering from durable
+acknowledgements on every request. Default identity reads retain the full run.
+Stored payloads and separate native tool authorization checks remain unchanged.
+
 Native event acknowledgements read a count and maximum through the existing
 source-sequence index. A stream with gaps uses indexed lookups for its first
 missing successor. The acknowledgement keeps its contiguous-prefix rule without
 returning every historical sequence number. All events stay stored. Counting the
 index entries still grows with the stream length.
 
+Conversation recovery reads only the saved run fields used to settle a turn.
+Settlement locks and reads current conversation state without loading the task
+description or comment bodies. It still checks the durable reply or pending
+interaction, session generation, owning run, and newer user messages. Saved
+execution payloads, task text, and comments remain stored in full.
+
 The attention feed checks for newer runs with company-scoped existence probes.
 The probes match the failed run's agent and issue or task context. They preserve
 the existing millisecond comparison and empty-context rules. Each batch holds