BOLT-1061: semantic idempotency key implementation

Started BOLT-1061 implementation on branch talos/bolt-1061-semantic-idempotency in worktree ~/Development/mono-bolt-1061.

BOLT-1061 branch pushed: talos/bolt-1061-semantic-idempotency (commit 7d82ebc0c6). Local go test ./... and go build ./... passed; pnpm lint --filter device-detected-ingestor exited because repo packageManager is yarn.

Opened BOLT-1061 implementation PR #11333: https://github.com/TextureHQ/mono/pull/11333

Addressed Cursor Bugbot high-severity replay-detection finding in PR #11333 with b06fd8715f; resolved review thread. Local go test ./... and go build ./... passed before push.

Addressed PR #11333 Cursor/CodeRabbit idempotency review findings: removed tag.Insert replay detection via DO NOTHING + replay metadata update (commit b06fd8715f), made semantic key unique index partial and hardened embed test (commit f0f3d97617). Local go test ./... and go vet ./... passed; CI re-running.

Addressed Cursor Bugbot partial-index inference finding in PR #11333 with cabe060048; resolved thread. Local go test ./... and go build ./... passed before push.

Addressed final Cursor Bugbot findings in PR #11333 with 2a4a6baf8c: deterministic invalid-createdAt semantic key fallback and removed processorSemanticRecord indirection. Local go test ./... and go build ./... passed before push; review threads resolved.

Addressed latest Cursor Bugbot edge cases in PR #11333 with 3d003c86dc: legacy event_id row claim on flag flip and invalid-createdAt normalization isolated to semantic key. Local go test ./... and go build ./... passed before push; threads resolved.

Addressed new CodeRabbit review findings in PR #11333 with 9064b40220: legacy event_id rows now short-circuit without rerunning side effects, and zero Kafka timestamp fallback is retry-stable rather than clock.Now. Local go test ./... and go build ./... passed; CI re-running.

Addressed Cursor Bugbot low-severity findings in PR #11333 with 5380e6da23: semantic pending reason and removed unused clock parameter. Local go test ./... and go build ./... passed before push; threads resolved.