feat(desktop): harness-agnostic config bridge

Four-tier config bridge that reads agent configuration from config
files (goose YAML, claude JSON, codex TOML), ACP session data, env
vars, and Sprout-explicit overrides — surfacing a unified normalized
config surface to the desktop UI regardless of runtime.

Key changes:
- Config bridge module with per-runtime file readers
- ACP session config caching for post-spawn config visibility
- AgentConfigPanel component with origin badges and tier provenance
- Serde internally-tagged enums matching TypeScript discriminated unions
- TOCTOU-safe write path with single lock scope
- E2E mock handler for get_agent_config_surface with per-runtime
  fixtures and a Playwright screenshot spec covering 7 scenarios
- Info icon + tooltip on read-only fields; override/strikethrough
  rendering for superseded config values

Co-authored-by: Will Pfleger <pfleger.will@gmail.com>
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>

.github/workflows/ci.yml

@@ -357,8 +357,10 @@ jobs:
           wait_healthy "Redis" "buzz-redis"
           wait_healthy "Typesense" "buzz-typesense"
           wait_healthy "MinIO" "buzz-minio"
+      - name: Create pgschema plan database
+        run: PGPASSWORD=buzz_dev createdb -h localhost -p 5432 -U buzz pgschema_plan
       - name: Apply database schema
-        run: ./bin/pgschema apply --file schema/schema.sql --auto-approve
+        run: ./bin/pgschema apply --file schema/schema.sql --auto-approve --plan-host localhost --plan-port 5432 --plan-user buzz --plan-password buzz_dev --plan-db pgschema_plan
         env:
           PGHOST: localhost
           PGPORT: "5432"