Add --id flag to bd list for filtering by specific issue IDs

- Add --id flag accepting comma-separated IDs
- Implements ID filtering at CLI, RPC, and storage layers
- Normalizes IDs (trim, dedupe, remove empty) like labels
- Guards against excessive ID lists (max 1000)
- Works with other filters (status, priority, etc.)

Closes bd-200

Amp-Thread-ID: https://ampcode.com/threads/T-377464f2-1e7f-46f9-b23e-1e3cfd611061
Co-authored-by: Amp <amp@ampcode.com>

internal/types/types.go

@@ -212,6 +212,7 @@ type IssueFilter struct {
 	Labels      []string  // AND semantics: issue must have ALL these labels
 	LabelsAny   []string  // OR semantics: issue must have AT LEAST ONE of these labels
 	TitleSearch string
+	IDs         []string  // Filter by specific issue IDs
 	Limit       int
 }