[DCV-3760][DCV-3765] Profiles.yml refresh + partial parse fallback

[jesusmgg]

Summary

• [DCV-3760] Track all potential profiles.yml paths (env var, project dir, ~/.dbt) in the watcher instead of only the resolved one at startup
• [DCV-3760] Re-resolve profiles_dir dynamically on reparse so the server switches when a higher-priority profiles.yml appears or the active one is deleted
• [DCV-3760] Re-resolve standard profiles_dir paths from state file on startup instead of using stale saved values. Custom (non-standard) paths are preserved.
• [DCV-3765] When partial parsing fails after new source files are created (e.g. dbt-coves generate sources), create a fresh ManifestLoader and do a full reparse. Fixes linting/formatting not working on newly generated files until page reload.

Test plan

• Modify ~/.dbt/profiles.yml, server reparses within 2s
• Copy profiles.yml to project dir, server switches to it
• Delete project dir profiles.yml, server falls back to ~/.dbt
• Custom profiles_dir (non-standard path) preserved across reparse
• Server recovers after fixing a broken profiles.yml
• Run dbt-coves generate sources, linting works on new files without page reload
• Existing file linting continues working after new files are generated
• No watcher crash loop after generating sources

After merge

git tag v1.1.7 && git push origin v1.1.7