Fix Dolt backend init/daemon/doctor; prevent accidental SQLite artifacts; add integration tests; clean up lint (#1218)

* /{cmd,internal}: get dolt backend init working and allow issue creation

* /{website,internal,docs,cmd}: integration tests and more split backend fixes

* /{cmd,internal}: fix lint issues

* /cmd/bd/doctor/integrity.go: fix unable to query issues bug with dolt backend

* /cmd/bd/daemon.go: remove debug logging

docs/QUICKSTART.md

@@ -18,6 +18,9 @@ First time in a repository:
 # Basic setup
 bd init
 
+# Dolt backend (version-controlled SQL database)
+bd init --backend dolt
+
 # OSS contributor (fork workflow with separate planning repo)
 bd init --contributor
 
@@ -35,6 +38,10 @@ The wizard will:
 - Prompt to configure git merge driver (recommended)
 - Auto-start daemon for sync
 
+Notes:
+- SQLite backend stores data in `.beads/beads.db`.
+- Dolt backend stores data in `.beads/dolt/` and records `"database": "dolt"` in `.beads/metadata.json`.
+
 ## Your First Issues
 
 ```bash