fix: orphan detection false positive with dots in directory name

Only treat issue IDs as hierarchical (parent.child) when the dot appears
AFTER the first hyphen. This prevents false positives when the project
directory name contains a dot (e.g., "my.project-abc123" was incorrectly
being treated as having parent "my").

Fixes GH#508

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/storage/sqlite/migrations/016_orphan_detection.go

@@ -16,13 +16,17 @@ import (
 // - Convert them to top-level issues by renaming them
 // - Restore the missing parent issues
 func MigrateOrphanDetection(db *sql.DB) error {
-	// Query for orphaned children using the pattern from the issue description:
-	// SELECT id FROM issues WHERE id LIKE '%.%'
-	// AND substr(id, 1, instr(id || '.', '.') - 1) NOT IN (SELECT id FROM issues)
+	// Query for orphaned children:
+	// - ID contains a dot (potential hierarchical structure)
+	// - The part before the first dot must contain a hyphen (GH#508)
+	//   This ensures the dot is in the hash portion (e.g., "bd-abc.1"), not in the prefix
+	//   (e.g., "my.project-abc123" where "my.project" is the prefix from directory name)
+	// - Parent (part before first dot) doesn't exist in database
 	rows, err := db.Query(`
 		SELECT id
 		FROM issues
 		WHERE id LIKE '%.%'
+		  AND instr(substr(id, 1, instr(id, '.') - 1), '-') > 0
 		  AND substr(id, 1, instr(id || '.', '.') - 1) NOT IN (SELECT id FROM issues)
 		ORDER BY id
 	`)