UI: password change enforcement + migration recovery

- Web UI admin password reset now enforces admin role
  server-side (was cookie-auth + CSRF only; any logged-in
  user could previously reset any account's password)
- Added self-service password change UI at GET/PUT /profile:
  current_password + new_password + confirm_password;
  server-side equality check; lockout + Argon2id verification;
  revokes all other sessions on success
- password_change_form.html fragment and profile.html page
- Nav bar actor name now links to /profile
- policy: ActionChangePassword + default rule -7 allowing
  human accounts to change their own password
- openapi.yaml: built-in rules count updated to -7

Migration recovery:
- mciasdb schema force --version N: new subcommand to clear
  dirty migration state without running SQL (break-glass)
- schema subcommands bypass auto-migration on open so the
  tool stays usable when the database is dirty
- Migrate(): shim no longer overrides schema_migrations
  when it already has an entry; duplicate-column error on
  the latest migration is force-cleaned and treated as
  success (handles columns added outside the runner)

Security:
- Admin role is now validated in handleAdminResetPassword
  before any DB access; non-admin receives 403
- handleSelfChangePassword follows identical lockout +
  constant-time Argon2id path as the REST self-service
  handler; current password required to prevent
  token-theft account takeover

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

internal/policy/defaults.go

@@ -42,6 +42,18 @@ var defaultRules = []Rule{
 		Actions:     []Action{ActionEnrollTOTP},
 		Effect:      Allow,
 	},
+	{
+		// Self-service password change: any authenticated human account may
+		// change their own password. The handler derives the target exclusively
+		// from the JWT subject (claims.Subject) and requires the current
+		// password, so a non-admin caller can only affect their own account.
+		ID:           -7,
+		Description:  "Self-service: any human account may change their own password",
+		Priority:     0,
+		AccountTypes: []string{"human"},
+		Actions:      []Action{ActionChangePassword},
+		Effect:       Allow,
+	},
 	{
 		// System accounts reading their own pgcreds: a service that has already
 		// authenticated (e.g. via its bearer service token) may retrieve its own