Remove vestigial --resolve-collisions flag

Hash-based IDs make collision resolution unnecessary. The flag was
already non-functional (handleCollisions returns error on collision
regardless of flag value).

Removed:
- --resolve-collisions flag from bd import
- ResolveCollisions field from ImportOptions and importer.Options
- All references in daemon, auto-import, and tests
- Updated error messages to reflect hash IDs don't collide

All import tests pass.

Amp-Thread-ID: https://ampcode.com/threads/T-47dfa0cc-bb71-4467-ac86-f0966a7c5d58
Co-authored-by: Amp <amp@ampcode.com>

cmd/bd/autoflush.go

@@ -168,7 +168,7 @@ func autoImportIfNewer() {
 	
 	// Use shared import logic (bd-157)
 	opts := ImportOptions{
-		ResolveCollisions:    true, // Auto-import always resolves collisions
+
 		DryRun:               false,
 		SkipUpdate:           false,
 		Strict:               false,

cmd/bd/autoimport.go

@@ -188,7 +188,7 @@ func importFromGit(ctx context.Context, dbFilePath string, store storage.Storage
 	// Note: SkipPrefixValidation allows mixed prefixes during auto-import
 	// (but now we set the prefix first, so CreateIssue won't use filename fallback)
 	opts := ImportOptions{
-		ResolveCollisions:  true,
+
 		DryRun:             false,
 		SkipUpdate:         false,
 		SkipPrefixValidation: true, // Auto-import is lenient about prefixes

cmd/bd/daemon.go

@@ -810,7 +810,7 @@ func importToJSONLWithStore(ctx context.Context, store storage.Storage, jsonlPat
 	
 	// Use existing import logic with auto-conflict resolution
 	opts := ImportOptions{
-		ResolveCollisions:    true,  // Auto-resolve ID conflicts
+
 		DryRun:              false,
 		SkipUpdate:          false,
 		Strict:              false,

cmd/bd/import.go

@@ -23,15 +23,13 @@ Reads from stdin by default, or use -i flag for file input.
 Behavior:
   - Existing issues (same ID) are updated
   - New issues are created
-  - Collisions (same ID, different content) are detected
-  - Use --resolve-collisions to automatically remap colliding issues
+  - Collisions (same ID, different content) are detected and reported
   - Use --dedupe-after to find and merge content duplicates after import
   - Use --dry-run to preview changes without applying them`,
 	Run: func(cmd *cobra.Command, args []string) {
 		input, _ := cmd.Flags().GetString("input")
 		skipUpdate, _ := cmd.Flags().GetBool("skip-existing")
 		strict, _ := cmd.Flags().GetBool("strict")
-		resolveCollisions, _ := cmd.Flags().GetBool("resolve-collisions")
 		dryRun, _ := cmd.Flags().GetBool("dry-run")
 		renameOnImport, _ := cmd.Flags().GetBool("rename-on-import")
 		dedupeAfter, _ := cmd.Flags().GetBool("dedupe-after")
@@ -86,7 +84,6 @@ Behavior:
 
 		// Phase 2: Use shared import logic
 		opts := ImportOptions{
-			ResolveCollisions: resolveCollisions,
 			DryRun:         dryRun,
 			SkipUpdate:     skipUpdate,
 			Strict:         strict,
@@ -112,14 +109,14 @@ Behavior:
 				os.Exit(1)
 			}
 			
-			// Check if it's a collision error when not resolving
-			if !resolveCollisions && result != nil && len(result.CollisionIDs) > 0 {
+			// Check if it's a collision error
+			if result != nil && len(result.CollisionIDs) > 0 {
 				// Print collision report before exiting
 				fmt.Fprintf(os.Stderr, "\n=== Collision Detection Report ===\n")
 				fmt.Fprintf(os.Stderr, "COLLISIONS DETECTED: %d\n\n", result.Collisions)
 				fmt.Fprintf(os.Stderr, "Colliding issue IDs: %v\n", result.CollisionIDs)
-				fmt.Fprintf(os.Stderr, "\nCollision detected! Use --resolve-collisions to automatically remap colliding issues.\n")
-				fmt.Fprintf(os.Stderr, "Or use --dry-run to preview without making changes.\n")
+				fmt.Fprintf(os.Stderr, "\nWith hash-based IDs, collisions should not occur.\n")
+				fmt.Fprintf(os.Stderr, "This may indicate manual ID manipulation or a bug.\n")
 				os.Exit(1)
 			}
 			fmt.Fprintf(os.Stderr, "Import failed: %v\n", err)
@@ -249,7 +246,6 @@ func init() {
 	importCmd.Flags().StringP("input", "i", "", "Input file (default: stdin)")
 	importCmd.Flags().BoolP("skip-existing", "s", false, "Skip existing issues instead of updating them")
 	importCmd.Flags().Bool("strict", false, "Fail on dependency errors instead of treating them as warnings")
-	importCmd.Flags().Bool("resolve-collisions", false, "Automatically resolve ID collisions by remapping")
 	importCmd.Flags().Bool("dedupe-after", false, "Detect and report content duplicates after import")
 	importCmd.Flags().Bool("dry-run", false, "Preview collision detection without making changes")
 	importCmd.Flags().Bool("rename-on-import", false, "Rename imported issues to match database prefix (updates all references)")

cmd/bd/import_bug_test.go

@@ -42,7 +42,7 @@ func TestImportReturnsCorrectCounts(t *testing.T) {
 
 	// Import with default options
 	opts := ImportOptions{
-		ResolveCollisions: false,
+
 		DryRun:            false,
 		SkipUpdate:        false,
 		Strict:            false,

cmd/bd/import_shared.go

@@ -158,7 +158,6 @@ func issueDataChanged(existing *types.Issue, updates map[string]interface{}) boo
 
 // ImportOptions configures how the import behaves
 type ImportOptions struct {
-	ResolveCollisions  bool // Auto-resolve collisions by remapping to new IDs
 	DryRun             bool // Preview changes without applying them
 	SkipUpdate         bool // Skip updating existing issues (create-only mode)
 	Strict             bool // Fail on any error (dependencies, labels, etc.)
@@ -194,7 +193,6 @@ type ImportResult struct {
 func importIssuesCore(ctx context.Context, dbPath string, store storage.Storage, issues []*types.Issue, opts ImportOptions) (*ImportResult, error) {
 	// Convert ImportOptions to importer.Options
 	importerOpts := importer.Options{
-		ResolveCollisions:    opts.ResolveCollisions,
 		DryRun:               opts.DryRun,
 		SkipUpdate:           opts.SkipUpdate,
 		Strict:               opts.Strict,

cmd/bd/jsonl_integrity_test.go

@@ -214,7 +214,7 @@ func TestImportClearsExportHashes(t *testing.T) {
 	}
 	
 	opts := ImportOptions{
-		ResolveCollisions:    false,
+
 		DryRun:               false,
 		SkipUpdate:           false,
 		Strict:               false,

internal/importer/importer.go

@@ -15,7 +15,6 @@ import (
 
 // Options contains import configuration
 type Options struct {
-	ResolveCollisions    bool // Auto-resolve collisions by remapping to new IDs
 	DryRun               bool // Preview changes without applying them
 	SkipUpdate           bool // Skip updating existing issues (create-only mode)
 	Strict               bool // Fail on any error (dependencies, labels, etc.)

internal/rpc/server_export_import_auto.go

@@ -209,7 +209,6 @@ func (s *Server) checkAndAutoImportIfStale(req *Request) error {
 	importFunc := func(ctx context.Context, issues []*types.Issue) (created, updated int, idMapping map[string]string, err error) {
 		// Use the importer package to perform the actual import
 		result, err := importer.ImportIssues(ctx, dbPath, store, issues, importer.Options{
-			ResolveCollisions: false, // Do NOT resolve collisions - update existing issues by ID
 			RenameOnImport: true, // Auto-rename prefix mismatches
 			// Note: SkipPrefixValidation is false by default, so we validate and rename
 		})