Enhance .gitignore created during bd init (#98)

- Expand .gitignore to include all SQLite-related files (journal, WAL, SHM)
- Add daemon runtime files (logs, PID, socket)
- Include legacy database filenames
- Explicitly allow JSONL files with !*.jsonl pattern
- Add test coverage to verify .gitignore content

cmd/bd/init.go

@@ -44,7 +44,24 @@ and database file. Optionally specify a custom issue prefix.`,
 
 		// Create .gitignore in .beads directory
 		gitignorePath := filepath.Join(beadsDir, ".gitignore")
-		gitignoreContent := "*.db\n*.db-*\n"
+		gitignoreContent := `# SQLite databases
+*.db
+*.db-journal
+*.db-wal
+*.db-shm
+
+# Daemon runtime files
+daemon.log
+daemon.pid
+bd.sock
+
+# Legacy database files
+db.sqlite
+bd.db
+
+# Keep JSONL exports (source of truth for git)
+!*.jsonl
+`
 		if err := os.WriteFile(gitignorePath, []byte(gitignoreContent), 0644); err != nil {
 			fmt.Fprintf(os.Stderr, "Warning: failed to create .gitignore: %v\n", err)
 			// Non-fatal - continue anyway

cmd/bd/init_test.go

@@ -113,6 +113,31 @@ func TestInitCommand(t *testing.T) {
 				t.Error(".beads directory was not created")
 			}
 
+			// Verify .gitignore was created with proper content
+			gitignorePath := filepath.Join(beadsDir, ".gitignore")
+			gitignoreContent, err := os.ReadFile(gitignorePath)
+			if err != nil {
+				t.Errorf(".gitignore file was not created: %v", err)
+			} else {
+				// Check for essential patterns
+				gitignoreStr := string(gitignoreContent)
+				expectedPatterns := []string{
+					"*.db",
+					"*.db-journal",
+					"*.db-wal",
+					"*.db-shm",
+					"daemon.log",
+					"daemon.pid",
+					"bd.sock",
+					"!*.jsonl",
+				}
+				for _, pattern := range expectedPatterns {
+					if !strings.Contains(gitignoreStr, pattern) {
+						t.Errorf(".gitignore missing expected pattern: %s", pattern)
+					}
+				}
+			}
+
 			// Verify database was created
 			var dbPath string
 			if tt.prefix != "" {

cmd/bd/testdata/init.txt

@@ -4,4 +4,10 @@ stdout 'initialized successfully'
 exists .beads/test.db
 exists .beads/.gitignore
 grep '^\*\.db$' .beads/.gitignore
-grep '^\*\.db-\*$' .beads/.gitignore
+grep '^\*\.db-journal$' .beads/.gitignore
+grep '^\*\.db-wal$' .beads/.gitignore
+grep '^\*\.db-shm$' .beads/.gitignore
+grep '^daemon\.log$' .beads/.gitignore
+grep '^daemon\.pid$' .beads/.gitignore
+grep '^bd\.sock$' .beads/.gitignore
+grep '^!\*\.jsonl$' .beads/.gitignore