Document root DBAL seed architecture: minimal bootstrap only

Add README to /dbal/shared/seeds/database explaining:
- Philosophy: Root seed = minimal, Packages = everything
- Structure: Only installed_packages.yaml and package_permissions.yaml
- Data flow: How bootstrap loads package entity folders
- What NOT to put here (all entity-specific data goes in packages)
- Idempotency guarantees
- How to add new core packages

This establishes the architecture:
1. DBAL seed contains only:
   - List of 12 core packages to install
   - System permissions and roles

2. Everything else goes in packages:
   - PageConfig (pages/routes)
   - Workflows
   - Credentials
   - Notifications
   - Components
   - Package-specific seed data

This clean separation means:
- Root DBAL is minimal and stable
- Packages are self-contained
- Easy to add/remove packages
- Clear organization

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

dbal/shared/seeds/README.md

@@ -0,0 +1,152 @@
+# Root DBAL Seed Data
+
+Minimal bootstrap seed data for the core system. Everything else belongs in packages.
+
+## Philosophy
+
+**Root DBAL seed = minimal. Packages = everything.**
+
+The root seed folder only contains what the DBAL needs to know about:
+- Which packages to install
+- System-wide permissions and roles
+
+All entity-specific seed data (pages, workflows, credentials, etc.) lives in the packages themselves.
+
+## Structure
+
+```
+dbal/shared/seeds/database/
+├── installed_packages.yaml    [List of 12 core packages]
+└── package_permissions.yaml   [System permissions]
+```
+
+That's it. Nothing else belongs here.
+
+## installed_packages.yaml
+
+Lists the 12 packages that bootstrap automatically:
+
+```yaml
+entity: InstalledPackage
+version: "1.0"
+records:
+  - packageId: package_manager
+    version: "1.0.0"
+    enabled: true
+    config: |
+      {
+        "autoUpdate": false,
+        "systemPackage": true
+      }
+
+  - packageId: ui_home
+    version: "1.0.0"
+    enabled: true
+    config: |
+      {
+        "systemPackage": true,
+        "defaultRoute": "/"
+      }
+
+  # ... 10 more packages
+```
+
+When bootstrap runs (`POST /api/bootstrap`):
+1. DBAL reads this file
+2. Creates InstalledPackage records for each
+3. For each package, looks for entity folders in `/packages/[packageId]/`
+4. Loads seed data from those entity folders
+
+## package_permissions.yaml
+
+System-wide permission and role definitions:
+
+```yaml
+entity: PackagePermission
+version: "1.0"
+records:
+  - id: perm_read_public_pages
+    packageId: null  # System-wide
+    permissionType: "resource"
+    resource: "page"
+    action: "read"
+    level: 0  # Public
+
+  # ... more permissions
+```
+
+These define who can do what with packages and resources.
+
+## Data Flow
+
+```
+/dbal/shared/seeds/database/installed_packages.yaml
+  ↓
+  1. DBAL reads package list
+  2. Creates InstalledPackage records
+  3. For each package, look for entity folders:
+    /packages/ui_home/page-config/
+    /packages/ui_home/workflow/
+    /packages/dashboard/page-config/
+    etc.
+  4. Load all seed data from those folders
+  5. Create records in database
+```
+
+## What Should NOT Go Here
+
+❌ PageConfig seed data (goes in `/packages/*/page-config/`)
+❌ Workflow definitions (goes in `/packages/*/workflow/`)
+❌ Notification templates (goes in `/packages/*/notification/`)
+❌ Component definitions (goes in `/packages/*/component/`)
+❌ Credential templates (goes in `/packages/*/credential/`)
+❌ Package-specific seed data (goes in packages)
+
+These belong in the packages because:
+1. They're specific to what each package provides
+2. Different installations might load different packages
+3. Packages are self-contained units
+
+## Idempotency
+
+All seed data is idempotent:
+- Run bootstrap 100 times, same result
+- Existing records are skipped
+- Safe to run multiple times
+
+## Adding a New Core Package
+
+To add a 13th package to bootstrap:
+
+1. Add to `installed_packages.yaml`:
+```yaml
+- packageId: new_package
+  version: "1.0.0"
+  enabled: true
+  config: |
+    {
+      "systemPackage": true
+    }
+```
+
+2. Create package folder: `/packages/new_package/`
+
+3. Add entity folders with seed data:
+```
+packages/new_package/
+├── page-config/
+│   ├── metadata.json
+│   └── pages.json
+└── workflow/
+    ├── metadata.json
+    └── workflows.json
+```
+
+4. Run bootstrap: `POST /api/bootstrap`
+
+## See Also
+
+- `/packages/PACKAGE_STRUCTURE.md` - Package organization
+- `/schemas/seed-data/` - JSON validation schemas
+- `/dbal/development/src/seeds/index.ts` - Seed orchestration
+- `/packages/SEED_FORMAT.md` - Seed data format