Add iMessage sync support

Implement a sync-imessage command that reads from macOS's
~/Library/Messages/chat.db and imports messages into the msgvault
archive using the existing sync infrastructure.

New files:
- internal/imessage/client.go: gmail.API implementation over chat.db
- internal/imessage/parser.go: MIME builder, timestamp conversion
- internal/imessage/models.go: chat.db row types
- internal/imessage/parser_test.go: tests for parsing utilities
- cmd/msgvault/cmd/sync_imessage.go: CLI command

Uses existing SourceType field in sync.Options (added by IMAP support).

Author: sternryan

cmd/msgvault/cmd/sync_imessage.go

@@ -0,0 +1,210 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"syscall"
+	"time"
+
+	"github.com/spf13/cobra"
+	"github.com/wesm/msgvault/internal/imessage"
+	"github.com/wesm/msgvault/internal/store"
+	"github.com/wesm/msgvault/internal/sync"
+)
+
+var (
+	imessageDBPath   string
+	imessageBefore   string
+	imessageAfter    string
+	imessageLimit    int
+	imessageMe       string
+	imessageNoResume bool
+)
+
+var syncImessageCmd = &cobra.Command{
+	Use:   "sync-imessage",
+	Short: "Import iMessages from local database",
+	Long: `Import iMessages from macOS's local Messages database (chat.db).
+
+Reads messages from ~/Library/Messages/chat.db and stores them in the
+msgvault archive alongside Gmail messages. This is a read-only operation
+that does not modify the iMessage database.
+
+Requires Full Disk Access permission in System Settings > Privacy & Security.
+
+Date filters:
+  --after 2024-01-01     Only messages on or after this date
+  --before 2024-12-31    Only messages before this date
+
+Examples:
+  msgvault sync-imessage
+  msgvault sync-imessage --after 2024-01-01
+  msgvault sync-imessage --limit 100
+  msgvault sync-imessage --me "+15551234567"
+  msgvault sync-imessage --db-path /path/to/chat.db`,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		// Open msgvault database
+		dbPath := cfg.DatabaseDSN()
+		s, err := store.Open(dbPath)
+		if err != nil {
+			return fmt.Errorf("open database: %w", err)
+		}
+		defer s.Close()
+
+		if err := s.InitSchema(); err != nil {
+			return fmt.Errorf("init schema: %w", err)
+		}
+
+		// Resolve chat.db path
+		chatDBPath := imessageDBPath
+		if chatDBPath == "" {
+			home, err := os.UserHomeDir()
+			if err != nil {
+				return fmt.Errorf("get home directory: %w", err)
+			}
+			chatDBPath = filepath.Join(home, "Library", "Messages", "chat.db")
+		}
+
+		// Check chat.db exists
+		if _, err := os.Stat(chatDBPath); os.IsNotExist(err) {
+			return fmt.Errorf("iMessage database not found at %s\n\nMake sure you're running on macOS with Messages enabled", chatDBPath)
+		}
+
+		// Build client options
+		var clientOpts []imessage.ClientOption
+		clientOpts = append(clientOpts, imessage.WithImessageLogger(logger))
+
+		if imessageMe != "" {
+			clientOpts = append(clientOpts, imessage.WithMyAddress(imessageMe))
+		}
+
+		if imessageAfter != "" {
+			t, err := time.Parse("2006-01-02", imessageAfter)
+			if err != nil {
+				return fmt.Errorf("invalid --after date: %w (use YYYY-MM-DD format)", err)
+			}
+			clientOpts = append(clientOpts, imessage.WithAfterDate(t))
+		}
+
+		if imessageBefore != "" {
+			t, err := time.Parse("2006-01-02", imessageBefore)
+			if err != nil {
+				return fmt.Errorf("invalid --before date: %w (use YYYY-MM-DD format)", err)
+			}
+			clientOpts = append(clientOpts, imessage.WithBeforeDate(t))
+		}
+
+		if imessageLimit > 0 {
+			clientOpts = append(clientOpts, imessage.WithLimit(imessageLimit))
+		}
+
+		// Determine source identifier
+		identifier := "local"
+		if imessageMe != "" {
+			identifier = imessageMe
+		}
+
+		// Create iMessage client
+		imsgClient, err := imessage.NewClient(chatDBPath, identifier, clientOpts...)
+		if err != nil {
+			return fmt.Errorf("open iMessage database: %w", err)
+		}
+		defer imsgClient.Close()
+
+		// Set up context with cancellation
+		ctx, cancel := context.WithCancel(cmd.Context())
+		defer cancel()
+
+		// Handle Ctrl+C gracefully
+		sigChan := make(chan os.Signal, 1)
+		signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+		go func() {
+			<-sigChan
+			fmt.Println("\nInterrupted. Saving checkpoint...")
+			cancel()
+		}()
+
+		// Set up sync options
+		opts := sync.DefaultOptions()
+		opts.NoResume = imessageNoResume
+		opts.SourceType = "apple_messages"
+		opts.AttachmentsDir = cfg.AttachmentsDir()
+
+		// Create syncer with progress reporter
+		syncer := sync.New(imsgClient, s, opts).
+			WithLogger(logger).
+			WithProgress(&CLIProgress{})
+
+		// Run sync
+		startTime := time.Now()
+		fmt.Printf("Starting iMessage sync from %s\n", chatDBPath)
+		if imessageAfter != "" || imessageBefore != "" {
+			parts := []string{}
+			if imessageAfter != "" {
+				parts = append(parts, "after "+imessageAfter)
+			}
+			if imessageBefore != "" {
+				parts = append(parts, "before "+imessageBefore)
+			}
+			fmt.Printf("Date filter: %s\n", joinParts(parts))
+		}
+		if imessageLimit > 0 {
+			fmt.Printf("Limit: %d messages\n", imessageLimit)
+		}
+		fmt.Println()
+
+		summary, err := syncer.Full(ctx, identifier)
+		if err != nil {
+			if ctx.Err() != nil {
+				fmt.Println("\nSync interrupted. Run again to resume.")
+				return nil
+			}
+			return fmt.Errorf("sync failed: %w", err)
+		}
+
+		// Print summary
+		fmt.Println()
+		fmt.Println("iMessage sync complete!")
+		fmt.Printf("  Duration:      %s\n", summary.Duration.Round(time.Second))
+		fmt.Printf("  Messages:      %d found, %d added, %d skipped\n",
+			summary.MessagesFound, summary.MessagesAdded, summary.MessagesSkipped)
+		if summary.Errors > 0 {
+			fmt.Printf("  Errors:        %d\n", summary.Errors)
+		}
+		if summary.WasResumed {
+			fmt.Printf("  (Resumed from checkpoint)\n")
+		}
+
+		if summary.MessagesAdded > 0 {
+			elapsed := time.Since(startTime)
+			messagesPerSec := float64(summary.MessagesAdded) / elapsed.Seconds()
+			fmt.Printf("  Rate:          %.1f messages/sec\n", messagesPerSec)
+		}
+
+		return nil
+	},
+}
+
+func joinParts(parts []string) string {
+	result := ""
+	for i, p := range parts {
+		if i > 0 {
+			result += ", "
+		}
+		result += p
+	}
+	return result
+}
+
+func init() {
+	syncImessageCmd.Flags().StringVar(&imessageDBPath, "db-path", "", "path to chat.db (default: ~/Library/Messages/chat.db)")
+	syncImessageCmd.Flags().StringVar(&imessageBefore, "before", "", "only messages before this date (YYYY-MM-DD)")
+	syncImessageCmd.Flags().StringVar(&imessageAfter, "after", "", "only messages after this date (YYYY-MM-DD)")
+	syncImessageCmd.Flags().IntVar(&imessageLimit, "limit", 0, "limit number of messages (for testing)")
+	syncImessageCmd.Flags().StringVar(&imessageMe, "me", "", "your phone number or email (e.g., +15551234567)")
+	syncImessageCmd.Flags().BoolVar(&imessageNoResume, "noresume", false, "force fresh sync (don't resume)")
+	rootCmd.AddCommand(syncImessageCmd)
+}