Idempotent keystroke recovery through Echo WAL #86

Summary

Explore crash-proof editing sessions where significant keystrokes, commands, or macro executions become deterministic Echo intents and can be recovered from WAL posture after restart.

Assessment

This is an excellent north-star UX, but the granularity needs care. Every raw keystroke as an intent may be too expensive/noisy; command batches, insert spans, macro invocations, and save checkpoints are more likely to be the right first proof. The idea is still structurally right: the editor should recover from Echo causal evidence, not volatile app undo state.

Proposed Experience

• User edits normally.
• Jedit batches meaningful editing actions into deterministic intents with stable ids.
• If the terminal or process crashes, restart recovers the pending/session history from Echo WAL evidence.
• The user can jump to exact ticks or replay command batches from the session.

Design Constraints

• Need a batching policy so intent history remains useful and performant.
• Recovery must distinguish admitted edits, pending submissions, rejected edits, and materialized saves.
• Jedit should not keep a private causal fallback log.

Proof Sketch

• Start an editing session and submit several command batches.
• Simulate process crash before normal app shutdown.
• Restart and recover from Echo evidence.
• Assert buffer content, dirty state, and edit history posture match recovered causal history.