feat: Complete command set standardization (bd-au0)

Epic bd-au0: Command Set Standardization & Flag Consistency

Completed all 10 child issues:

P0 tasks:
- Standardize --dry-run flag across all commands (bd-au0.1)
- Add label operations to bd update (bd-au0.2)
- Fix --title vs --title-contains redundancy (bd-au0.3)
- Standardize priority flag parsing (bd-au0.4)

P1 tasks:
- Add date/priority filters to bd search (bd-au0.5)
- Add comprehensive filters to bd export (bd-au0.6)
- Audit and standardize JSON output (bd-au0.7)

P2 tasks:
- Improve clean vs cleanup documentation (bd-au0.8)
- Document rarely-used commands (bd-au0.9)

P3 tasks:
- Add global verbosity flags --verbose/-v and --quiet/-q (bd-au0.10)

Key changes:
- export.go: Added filters (assignee, type, labels, priority, dates)
- main.go: Added --verbose/-v and --quiet/-q global flags
- debug.go: Added SetVerbose/SetQuiet and PrintNormal helpers
- clean.go/cleanup.go: Improved documentation with cross-references
- detect_pollution.go: Added use cases and warnings
- migrate_hash_ids.go: Marked as legacy command
- rename_prefix.go: Added use cases documentation

All success criteria met: flags standardized, feature parity achieved,
naming clarified, JSON output consistent.

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

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

cmd/bd/export.go

@@ -14,6 +14,8 @@ import (
 	"github.com/steveyegge/beads/internal/debug"
 	"github.com/steveyegge/beads/internal/storage/sqlite"
 	"github.com/steveyegge/beads/internal/types"
+	"github.com/steveyegge/beads/internal/util"
+	"github.com/steveyegge/beads/internal/validation"
 )
 
 // countIssuesInJSONL counts the number of issues in a JSONL file
@@ -114,13 +116,30 @@ var exportCmd = &cobra.Command{
 	Long: `Export all issues to JSON Lines format (one JSON object per line).
 Issues are sorted by ID for consistent diffs.
 
-Output to stdout by default, or use -o flag for file output.`,
+Output to stdout by default, or use -o flag for file output.
+
+Examples:
+  bd export --status open -o open-issues.jsonl
+  bd export --type bug --priority-max 1
+  bd export --created-after 2025-01-01 --assignee alice`,
 	Run: func(cmd *cobra.Command, args []string) {
 		format, _ := cmd.Flags().GetString("format")
 		output, _ := cmd.Flags().GetString("output")
 		statusFilter, _ := cmd.Flags().GetString("status")
 		force, _ := cmd.Flags().GetBool("force")
-		
+
+		// Additional filter flags
+		assignee, _ := cmd.Flags().GetString("assignee")
+		issueType, _ := cmd.Flags().GetString("type")
+		labels, _ := cmd.Flags().GetStringSlice("label")
+		labelsAny, _ := cmd.Flags().GetStringSlice("label-any")
+		priorityMinStr, _ := cmd.Flags().GetString("priority-min")
+		priorityMaxStr, _ := cmd.Flags().GetString("priority-max")
+		createdAfter, _ := cmd.Flags().GetString("created-after")
+		createdBefore, _ := cmd.Flags().GetString("created-before")
+		updatedAfter, _ := cmd.Flags().GetString("updated-after")
+		updatedBefore, _ := cmd.Flags().GetString("updated-before")
+
 		debug.Logf("Debug: export flags - output=%q, force=%v\n", output, force)
 
 		if format != "jsonl" {
@@ -155,12 +174,81 @@ Output to stdout by default, or use -o flag for file output.`,
 			defer func() { _ = store.Close() }()
 		}
 
+		// Normalize labels: trim, dedupe, remove empty
+		labels = util.NormalizeLabels(labels)
+		labelsAny = util.NormalizeLabels(labelsAny)
+
 		// Build filter
 		filter := types.IssueFilter{}
 		if statusFilter != "" {
 			status := types.Status(statusFilter)
 			filter.Status = &status
 		}
+		if assignee != "" {
+			filter.Assignee = &assignee
+		}
+		if issueType != "" {
+			t := types.IssueType(issueType)
+			filter.IssueType = &t
+		}
+		if len(labels) > 0 {
+			filter.Labels = labels
+		}
+		if len(labelsAny) > 0 {
+			filter.LabelsAny = labelsAny
+		}
+
+		// Priority ranges
+		if cmd.Flags().Changed("priority-min") {
+			priorityMin, err := validation.ValidatePriority(priorityMinStr)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Error parsing --priority-min: %v\n", err)
+				os.Exit(1)
+			}
+			filter.PriorityMin = &priorityMin
+		}
+		if cmd.Flags().Changed("priority-max") {
+			priorityMax, err := validation.ValidatePriority(priorityMaxStr)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Error parsing --priority-max: %v\n", err)
+				os.Exit(1)
+			}
+			filter.PriorityMax = &priorityMax
+		}
+
+		// Date ranges
+		if createdAfter != "" {
+			t, err := parseTimeFlag(createdAfter)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Error parsing --created-after: %v\n", err)
+				os.Exit(1)
+			}
+			filter.CreatedAfter = &t
+		}
+		if createdBefore != "" {
+			t, err := parseTimeFlag(createdBefore)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Error parsing --created-before: %v\n", err)
+				os.Exit(1)
+			}
+			filter.CreatedBefore = &t
+		}
+		if updatedAfter != "" {
+			t, err := parseTimeFlag(updatedAfter)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Error parsing --updated-after: %v\n", err)
+				os.Exit(1)
+			}
+			filter.UpdatedAfter = &t
+		}
+		if updatedBefore != "" {
+			t, err := parseTimeFlag(updatedBefore)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Error parsing --updated-before: %v\n", err)
+				os.Exit(1)
+			}
+			filter.UpdatedBefore = &t
+		}
 
 		// Get all issues
 		ctx := rootCtx
@@ -421,5 +509,22 @@ func init() {
 	exportCmd.Flags().StringP("status", "s", "", "Filter by status")
 	exportCmd.Flags().Bool("force", false, "Force export even if database is empty")
 	exportCmd.Flags().BoolVar(&jsonOutput, "json", false, "Output export statistics in JSON format")
+
+	// Filter flags
+	exportCmd.Flags().StringP("assignee", "a", "", "Filter by assignee")
+	exportCmd.Flags().StringP("type", "t", "", "Filter by type (bug, feature, task, epic, chore)")
+	exportCmd.Flags().StringSliceP("label", "l", []string{}, "Filter by labels (AND: must have ALL)")
+	exportCmd.Flags().StringSlice("label-any", []string{}, "Filter by labels (OR: must have AT LEAST ONE)")
+
+	// Priority filters
+	exportCmd.Flags().String("priority-min", "", "Filter by minimum priority (inclusive, 0-4 or P0-P4)")
+	exportCmd.Flags().String("priority-max", "", "Filter by maximum priority (inclusive, 0-4 or P0-P4)")
+
+	// Date filters
+	exportCmd.Flags().String("created-after", "", "Filter issues created after date (YYYY-MM-DD or RFC3339)")
+	exportCmd.Flags().String("created-before", "", "Filter issues created before date (YYYY-MM-DD or RFC3339)")
+	exportCmd.Flags().String("updated-after", "", "Filter issues updated after date (YYYY-MM-DD or RFC3339)")
+	exportCmd.Flags().String("updated-before", "", "Filter issues updated before date (YYYY-MM-DD or RFC3339)")
+
 	rootCmd.AddCommand(exportCmd)
 }