Reconcile missing context-compaction transcript notes on load

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What happened

A successful explicit context-compaction turn can durably commit its terminal RuntimeEvent before its transcript context_compacted system note is written. If the process crashes in that interval, or all bounded note-write retries fail, reopening the session shows a completed compaction with no durable transcript row.

The canonical terminal fact already exists: the compaction turn's RuntimeEvent contains stateDelta.contextCompactionOutcome. Terminal transcript reads do not use a live overlay, and later passive checkpoint replay intentionally does not emit another note, so the missing row is not repaired.

Expected: session load/recovery idempotently reconciles a terminal context-compaction outcome into exactly one matching durable system note.

How to reproduce

1. Complete an explicit context compaction.
2. Inject a process crash after the terminal RuntimeEvent commit and before appendDurableCompactionNote, or make all three appendMessage attempts fail.
3. Reopen the session.
4. Observe that the compaction turn is terminal but no context_compacted row is present.

A fault-injection regression should cover the crash window and prove repeated recovery cannot duplicate the note.

Environment

• Maka: follow-up to PR feat(desktop): show context compaction in transcript #3651
• Surface: Runtime / Runtime Host / Desktop transcript
• OS: all

Logs, screenshots, or additional context

PR #3651 intentionally uses a bounded three-attempt retry with one stable note id. That handles transient storage errors in-process, but cannot close the crash window. Implement reconcile-on-load from the canonical terminal RuntimeEvent, preserving these semantics:

• compacted → exactly one context_compacted note
• failed → exactly one context_compaction_failed_open note
• unchanged or interrupted → no durable note
• recovery is idempotent and never duplicates an already-written note

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