fix(05-06): add Collection and Remittance CASL subjects, update routes

- Add Collection and Remittance to AppSubjects union type
- Grant OFFICE_STAFF manage:Collection and manage:Remittance
- Grant COLLECTOR create/read:Collection and create/read:Remittance
- Update all 8 collection/remittance route handlers from Subscriber to
  their dedicated CASL subjects (Collection or Remittance)
- Update JSDoc comments in route files to reflect new subject names

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/lib/casl/permissions.ts

@@ -66,6 +66,9 @@ export function definePermissionsFor(
       can("manage", "Expense");
       // Vendor management (CRUD)
       can("manage", "Vendor");
+      // Collection and remittance management
+      can("manage", "Collection");
+      can("manage", "Remittance");
       // Job type rates (read-only for office staff — admin configures rates)
       can("read", "JobTypeRate");
       // View financial reports (read-only)
@@ -88,6 +91,12 @@ export function definePermissionsFor(
       can("create", "Payment");
       // View payment history
       can("read", "Payment");
+      // Can create and view collections
+      can("create", "Collection");
+      can("read", "Collection");
+      // Can create and view remittances
+      can("create", "Remittance");
+      can("read", "Remittance");
       // NOTE: No explicit cannot() needed — Collector simply has no rules for
       // Invoice, User management, or Reports. Absence of a rule = no access.
       break;