* refactor(doctor): split doctor.go into modular package files
Split the 3,171-line doctor.go into logical sub-files within the
cmd/bd/doctor/ package, reducing the main file to 834 lines (74% reduction).
New package structure:
- types.go: DoctorCheck struct and status constants
- installation.go: CheckInstallation, CheckMultipleDatabases, CheckPermissions
- git.go: CheckGitHooks, CheckMergeDriver, CheckSyncBranch* checks
- database.go: CheckDatabaseVersion, CheckSchemaCompatibility, CheckDatabaseJSONLSync
- version.go: CheckCLIVersion, CheckMetadataVersionTracking, CompareVersions
- integrity.go: CheckIDFormat, CheckDependencyCycles, CheckTombstones
- daemon.go: CheckDaemonStatus, CheckVersionMismatch
- quick.go: Quick checks for sync-branch and hooks
Updated tests to use exported doctor.CheckXxx() functions and
doctor.StatusXxx constants.
* fix(doctor): suppress gosec G204 false positives
Add #nosec G204 comments to exec.Command calls in CheckSyncBranchHealth
where variables come from trusted sources (config files or hardcoded
values like "main"/"master"/"origin"), not untrusted user input.
e9be35e374