fix(sync): protect locally exported issues from sanitization (bd-3ee1)

The sync sanitize process was incorrectly removing newly created issues
when they happened to have IDs matching entries in the deletions manifest.
This could occur with hash-based IDs when content is similar to previously
deleted issues.

The fix adds protection for issues that were in the left snapshot (local
export before pull). These represent local work and should not be removed
by sanitize, even if they match entries in the deletions manifest.

Changes:
- Load left snapshot in sanitizeJSONLWithDeletions() to build protection set
- Add protection check before removing issues from JSONL
- Add ProtectedCount/ProtectedIDs to SanitizeResult for tracking
- Log protected issues during sync for visibility
- Add comprehensive test coverage for the fix

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/bd/sync.go

@@ -580,10 +580,19 @@ Use --merge to merge the sync branch back to main branch.`,
 				if err != nil {
 					fmt.Fprintf(os.Stderr, "Warning: failed to sanitize JSONL: %v\n", err)
 					// Non-fatal - continue with import
-				} else if sanitizeResult.RemovedCount > 0 {
-					fmt.Printf("→ Sanitized JSONL: removed %d deleted issue(s) that were resurrected by git merge\n", sanitizeResult.RemovedCount)
-					for _, id := range sanitizeResult.RemovedIDs {
-						fmt.Printf("  - %s\n", id)
+				} else {
+					// bd-3ee1 fix: Log protected issues (local work that would have been incorrectly removed)
+					if sanitizeResult.ProtectedCount > 0 {
+						fmt.Printf("→ Protected %d locally exported issue(s) from incorrect sanitization (bd-3ee1)\n", sanitizeResult.ProtectedCount)
+						for _, id := range sanitizeResult.ProtectedIDs {
+							fmt.Printf("  - %s (in left snapshot)\n", id)
+						}
+					}
+					if sanitizeResult.RemovedCount > 0 {
+						fmt.Printf("→ Sanitized JSONL: removed %d deleted issue(s) that were resurrected by git merge\n", sanitizeResult.RemovedCount)
+						for _, id := range sanitizeResult.RemovedIDs {
+							fmt.Printf("  - %s\n", id)
+						}
 					}
 				}
 
@@ -1717,8 +1726,10 @@ func maybeAutoCompactDeletions(ctx context.Context, jsonlPath string) error {
 
 // SanitizeResult contains statistics about the JSONL sanitization operation.
 type SanitizeResult struct {
-	RemovedCount int      // Number of issues removed from JSONL
-	RemovedIDs   []string // IDs that were removed
+	RemovedCount    int      // Number of issues removed from JSONL
+	RemovedIDs      []string // IDs that were removed
+	ProtectedCount  int      // Number of issues protected from removal (bd-3ee1)
+	ProtectedIDs    []string // IDs that were protected
 }
 
 // sanitizeJSONLWithDeletions removes non-tombstone issues from the JSONL file
@@ -1730,10 +1741,17 @@ type SanitizeResult struct {
 // the importer to re-create tombstones from deletions.jsonl, leading to
 // UNIQUE constraint errors when the tombstone already exists in the database.
 //
+// IMPORTANT (bd-3ee1 fix): Issues that were in the left snapshot (local export
+// before pull) are protected from removal. This prevents newly created issues
+// from being incorrectly removed when they happen to have an ID that matches
+// an entry in the deletions manifest (possible with hash-based IDs if content
+// is similar to a previously deleted issue).
+//
 // This should be called after git pull but before import.
 func sanitizeJSONLWithDeletions(jsonlPath string) (*SanitizeResult, error) {
 	result := &SanitizeResult{
-		RemovedIDs: []string{},
+		RemovedIDs:   []string{},
+		ProtectedIDs: []string{},
 	}
 
 	// Get deletions manifest path
@@ -1751,6 +1769,16 @@ func sanitizeJSONLWithDeletions(jsonlPath string) (*SanitizeResult, error) {
 		return result, nil
 	}
 
+	// bd-3ee1 fix: Load left snapshot to protect locally exported issues
+	// Issues in the left snapshot were exported before pull and represent
+	// local work that should not be removed by sanitize
+	sm := NewSnapshotManager(jsonlPath)
+	_, leftPath := sm.getSnapshotPaths()
+	protectedIDs := make(map[string]bool)
+	if leftIDs, err := sm.buildIDSet(leftPath); err == nil && len(leftIDs) > 0 {
+		protectedIDs = leftIDs
+	}
+
 	// Read current JSONL
 	f, err := os.Open(jsonlPath) // #nosec G304 - controlled path
 	if err != nil {
@@ -1790,6 +1818,12 @@ func sanitizeJSONLWithDeletions(jsonlPath string) (*SanitizeResult, error) {
 			if issue.Status == string(types.StatusTombstone) {
 				// Keep the tombstone - it's the authoritative deletion record
 				keptLines = append(keptLines, append([]byte{}, line...))
+			} else if protectedIDs[issue.ID] {
+				// bd-3ee1 fix: Issue was in left snapshot (local export before pull)
+				// This is local work, not a resurrected zombie - protect it!
+				keptLines = append(keptLines, append([]byte{}, line...))
+				result.ProtectedCount++
+				result.ProtectedIDs = append(result.ProtectedIDs, issue.ID)
 			} else {
 				// Remove non-tombstone issue that was resurrected
 				result.RemovedCount++