fix(central): review findings — no client-side audit truncation, insert-first upsert, QI-safe scripts, honest operator replies

Six adversarial-review findings in the central SQL/ingest layer.

F1 (AuditLogRepository.InsertChunkAsync) — the set-based ingest declared each
string parameter at its COLUMN width (Actor/Target 256, Action 64, Outcome 16,
Category 32, SourceNode 64), so SqlClient truncated an over-long value at bind
time and committed the mutilated row — silent, in an append-only store, with no
PayloadTruncated flag — while the per-row and reconciliation paths sent the same
value in full and let the server reject it with 2628. Bind at the value's own
length instead; explicit SqlDbType is kept (it fixes the VALUES constructor's
derived column types and datetime2 precision). Design: reject everywhere,
truncate nowhere — matching today's per-row behaviour.

F2 (SiteCallAuditRepository.UpsertAsync) — the single-statement upsert ran the
monotonic UPDATE first and INSERTed only if nothing matched. Two writers racing
the first packet of one TrackedOperationId (the cached dual-write and the
reconciliation pull carry DIFFERENT lifecycle states) both matched nothing, and
the loser then skipped its INSERT or swallowed a 2627 — dropping its
Status/RetryCount/HttpStatus/TerminalAtUtc. Legs swapped to
`IF NOT EXISTS … INSERT; UPDATE <monotonic>` — still one round trip, and the
loser's UPDATE now lands on the winner's row. The duplicate-key catch re-runs
the monotonic UPDATE for the same reason. Moved to raw SQL with explicitly-typed
parameters so the intricate rank predicate exists in exactly one place (an
untyped DateTime would bind as `datetime` and round the freshness tiebreaker).

F3 (docs/plans/sql/*.sql) — filtered-index DDL failed with error 1934 under the
documented `docker exec … sqlcmd` path, which defaults QUOTED_IDENTIFIER OFF;
once IX_Notifications_Delivered exists, QI-OFF DML on Notifications fails too.
All four scripts now open with `SET QUOTED_IDENTIFIER ON; SET ANSI_NULLS ON; GO`
(own batch, so it is in force when the next batch parses), and the migration
convention in Component-ConfigurationDatabase.md documents `sqlcmd -I`. Verified
live: the pre-fix script fails 1934 without -I, the fixed one applies.

F4 (SiteCallAuditActor) — the off-mailbox reconciliation/purge passes reuse the
injected repository, so tests drove one DbContext from the pass and a mailbox
handler concurrently. Serialized at the CALL via a private SerializedRepository
wrapper applied only by the test constructors, rather than running the pass
on-mailbox: production keeps its PipeTo shape untouched, and the existing
"a blocked drain does not stall ingest/query/KPI" regression tests stay
meaningful (they would have been invalidated by suspending the mailbox).

F5 (AuditLogIngestActor) — when the batch failed because the 20 s IngestBudget
expired, the per-row fallback reused the same expired token: N instant failures,
N counter bumps, zero accepted. The fallback now gets a fresh 5 s budget (inside
the 30 s outer Ask), and a blown budget bumps the failure counter ONCE for the
batch instead of once per row.

F6 (NotificationOutboxRepository.UpdateAsync) — ExecuteUpdate's row count was
discarded, so an operator Retry/Discard of a notification the retention purge had
already deleted reported success (the pre-ExecuteUpdate code threw
DbUpdateConcurrencyException). UpdateAsync now returns whether a row matched; the
operator one-shots answer "notification not found" and emit no audit row for the
action that did not happen, while the dispatcher logs a warning (its delivery
already happened; nothing to retry). GetByIdAsync switched to AsNoTracking since
the write is out-of-band.

Tests: 5 new SQL-backed regressions (over-long Target rejected on both paths +
boundary round-trip; concurrent first-write and already-created-by-another-writer
upserts; vanished-row UpdateAsync), a token-identity pin on the ingest fallback,
a repository-concurrency detector for the SiteCallAudit passes, and vanished-row
operator-path tests. The F1/F2/F4 regressions were each confirmed failing against
the pre-fix code. Suites: ConfigurationDatabase 369, AuditLog 378, SiteCallAudit
66, NotificationOutbox 152 — all green, solution builds with 0 warnings.

docs/requirements/Component-AuditLog.md

@@ -303,6 +303,24 @@ per-row / per-entry path — so the documented invariant that one bad row cannot
 sink the rest of the batch still holds, it is simply no longer paid for on the
 healthy path.
 
+The set-based path binds its string parameters at the VALUE's own length, never
+at the column width. Declaring the width makes the client TRUNCATE an over-long
+value at bind time and commit the shortened row — silent mutilation in an
+append-only store, with no `PayloadTruncated` flag to admit it, and inconsistent
+with the per-row and reconciliation paths, which send the value in full and let
+the server reject it. Length enforcement belongs to the server on every path:
+reject everywhere, truncate nowhere. (Deliberate, policy-driven truncation of
+`RequestSummary`/`ResponseSummary` under the payload caps is a different thing
+entirely — it happens before the write and always sets `PayloadTruncated`.)
+
+The per-row fallback runs on its OWN short cancellation budget rather than the
+batch's. Sharing it meant that a batch failing *because* the ingest budget
+expired handed every fallback insert an already-cancelled token: N instant
+failures, N counter bumps, nothing accepted — the fallback defeated at exactly
+the moment it was needed. A blown budget is also counted ONCE for the batch
+rather than once per row, so the health counter reads as one timeout instead of
+a burst of write failures.
+
 **Timeout ladder.** The ingest budget is deliberately the smallest on the path:
 the site's Ask and the central gRPC handler's Ask are both 30 s, the actor's
 own database budget is 20 s and the per-statement SQL timeout is 15 s. Before