Auto-save annotation drafts to survive server crashes

[backnotprop]

Summary

• Adds server-side draft persistence at ~/.plannotator/drafts/{content-hash}.json so annotations survive server crashes
• Debounced auto-save (500ms) on annotation changes — silent, no UI indicators
• On reload with existing draft, a dialog prompts to Restore or Dismiss
• Drafts auto-deleted on approve/deny/feedback submit
• Works across all three servers (plan, review, annotate)

Closes #212

Known limitation: Cross-block annotation highlights don't visually restore (pre-existing issue in findTextInDOM(), tracked in #216).

Test plan

• Add annotations to a plan, kill the server, restart with same plan content — dialog should appear
• Click Restore — annotations appear in sidebar panel
• Click Dismiss — draft deleted, no dialog on next reload
• Approve/deny a plan — draft file cleaned up
• Same flow works for code review (/plannotator-review)

🤖 Generated with Claude Code

[backnotprop]

Code review

Found 1 issue:

1. draftKey is computed once at server startup from options.rawPatch but never updated when the user switches diff types via /api/diff/switch. After a switch, currentPatch is updated (line 158) but all draft operations continue using the original key. If the server crashes after a diff switch, restored annotations will be applied against the wrong patch content.

plannotator/packages/server/review.ts

Lines 85 to 92 in 3df3e5d

	const draftKey = contentHash(options.rawPatch);
	// Mutable state for diff switching
	let currentPatch = options.rawPatch;
	let currentGitRef = options.gitRef;
	let currentDiffType: DiffType = options.diffType || "uncommitted";
	let currentError = options.error;

The /api/diff/switch handler updates currentPatch but not draftKey:

plannotator/packages/server/review.ts

Lines 156 to 161 in 3df3e5d

	// Update state
	currentPatch = result.patch;
	currentGitRef = result.label;
	currentDiffType = newDiffType;
	currentError = result.error;

🤖 Generated with Claude Code

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