feat: add history, retry, retention, and crash recovery

[douglasjarquin]

Summary

• Adds a lightweight AppKit history window backed by the existing file-based SessionStore.
• Adds bounded metadata-first history loading with lazy transcript detail reads.
• Adds launch interruption recovery, durable retry from audio.caf, recoverable transcript pruning, explicit deletion, and idle-only retention maintenance.
• Adds Copy Raw Transcript, Paste Again, Play Recording, Retry Transcription, Reveal Recording, and Delete Session actions with actionable user-facing errors.
• Preserves issue [02/13 · MVP] Build the native menu-bar shell and dictation state machine #3 through issue [05/13 · MVP] Insert the raw transcript into the original application #6 behavior, including failed-paste recovery and one-shot insertion.

Verification

• Issue [02/13 · MVP] Build the native menu-bar shell and dictation state machine #3, [03/13 · MVP] Add durable microphone capture and crash-recoverable sessions #4, [04/13 · MVP] Add on-device transcription and saved-audio retry #5, [05/13 · MVP] Insert the raw transcript into the original application #6, and [06/13 · Reliability] Add history, retry, retention, and crash recovery #7 executable contracts pass.
• Native Xcode build passes with DEVELOPER_DIR=/Applications/Xcode.app/Contents/Developer.
• Visual and operator QA covered the history/detail surface and all requested actions.
• The command-line host limitation for live microphone/speech capture remains documented by the issue [03/13 · MVP] Add durable microphone capture and crash-recoverable sessions #4 contract.

Closes #7