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/ui/handlers_auth.go

@@ -8,6 +8,7 @@ import (
 	"git.wntrmute.dev/kyle/mcias/internal/crypto"
 	"git.wntrmute.dev/kyle/mcias/internal/model"
 	"git.wntrmute.dev/kyle/mcias/internal/token"
+	"git.wntrmute.dev/kyle/mcias/internal/validate"
 )
 
 // handleLoginPage renders the login form.
@@ -255,3 +256,127 @@ func (u *UIServer) writeAudit(r *http.Request, eventType string, actorID, target
 		u.logger.Warn("write audit event", "type", eventType, "error", err)
 	}
 }
+
+// handleProfilePage renders the profile page for the currently logged-in user.
+func (u *UIServer) handleProfilePage(w http.ResponseWriter, r *http.Request) {
+	csrfToken, _ := u.setCSRFCookies(w)
+	u.render(w, "profile", ProfileData{
+		PageData: PageData{
+			CSRFToken: csrfToken,
+			ActorName: u.actorName(r),
+		},
+	})
+}
+
+// handleSelfChangePassword allows an authenticated human user to change their
+// own password.  The current password must be supplied to prevent a stolen
+// session token from being used to take over an account.
+//
+// Security: current password is verified with Argon2id (constant-time) before
+// the new hash is written.  Lockout is checked first so the endpoint cannot
+// be used to brute-force the existing password.  On success all other active
+// sessions are revoked; the caller's own session is preserved so they remain
+// logged in.  The plaintext passwords are never logged or returned.
+func (u *UIServer) handleSelfChangePassword(w http.ResponseWriter, r *http.Request) {
+	r.Body = http.MaxBytesReader(w, r.Body, maxFormBytes)
+	if err := r.ParseForm(); err != nil {
+		u.renderError(w, r, http.StatusBadRequest, "invalid form")
+		return
+	}
+
+	claims := claimsFromContext(r.Context())
+	if claims == nil {
+		u.renderError(w, r, http.StatusUnauthorized, "unauthorized")
+		return
+	}
+
+	acct, err := u.db.GetAccountByUUID(claims.Subject)
+	if err != nil {
+		u.renderError(w, r, http.StatusUnauthorized, "account not found")
+		return
+	}
+	if acct.AccountType != model.AccountTypeHuman {
+		u.renderError(w, r, http.StatusBadRequest, "password change is only available for human accounts")
+		return
+	}
+
+	currentPassword := r.FormValue("current_password")
+	newPassword := r.FormValue("new_password")
+	confirmPassword := r.FormValue("confirm_password")
+
+	if currentPassword == "" || newPassword == "" {
+		u.renderError(w, r, http.StatusBadRequest, "current and new password are required")
+		return
+	}
+	// Server-side confirmation check mirrors the client-side guard; defends
+	// against direct POST requests that bypass the JavaScript validation.
+	if newPassword != confirmPassword {
+		u.renderError(w, r, http.StatusBadRequest, "passwords do not match")
+		return
+	}
+
+	// Security: check lockout before running Argon2 to prevent brute-force.
+	locked, lockErr := u.db.IsLockedOut(acct.ID)
+	if lockErr != nil {
+		u.logger.Error("lockout check (UI self-service password change)", "error", lockErr)
+	}
+	if locked {
+		u.writeAudit(r, model.EventPasswordChanged, &acct.ID, &acct.ID, `{"result":"locked"}`)
+		u.renderError(w, r, http.StatusTooManyRequests, "account temporarily locked, please try again later")
+		return
+	}
+
+	// Security: verify current password with constant-time Argon2id path used
+	// at login so this endpoint cannot serve as a timing oracle.
+	ok, verifyErr := auth.VerifyPassword(currentPassword, acct.PasswordHash)
+	if verifyErr != nil || !ok {
+		_ = u.db.RecordLoginFailure(acct.ID)
+		u.writeAudit(r, model.EventPasswordChanged, &acct.ID, &acct.ID, `{"result":"wrong_current_password"}`)
+		u.renderError(w, r, http.StatusUnauthorized, "current password is incorrect")
+		return
+	}
+
+	// Security (F-13): enforce minimum length before hashing.
+	if err := validate.Password(newPassword); err != nil {
+		u.renderError(w, r, http.StatusBadRequest, err.Error())
+		return
+	}
+
+	hash, err := auth.HashPassword(newPassword, auth.ArgonParams{
+		Time:    u.cfg.Argon2.Time,
+		Memory:  u.cfg.Argon2.Memory,
+		Threads: u.cfg.Argon2.Threads,
+	})
+	if err != nil {
+		u.logger.Error("hash password (UI self-service)", "error", err)
+		u.renderError(w, r, http.StatusInternalServerError, "internal error")
+		return
+	}
+
+	if err := u.db.UpdatePasswordHash(acct.ID, hash); err != nil {
+		u.logger.Error("update password hash", "error", err)
+		u.renderError(w, r, http.StatusInternalServerError, "failed to update password")
+		return
+	}
+
+	// Security: clear failure counter (user proved knowledge of current
+	// password), then revoke all sessions except the current one so stale
+	// tokens are invalidated while the caller stays logged in.
+	_ = u.db.ClearLoginFailures(acct.ID)
+	if err := u.db.RevokeAllUserTokensExcept(acct.ID, claims.JTI, "password_changed"); err != nil {
+		u.logger.Error("revoke other tokens on UI password change", "account_id", acct.ID, "error", err)
+		u.renderError(w, r, http.StatusInternalServerError, "password updated but session revocation failed; revoke tokens manually")
+		return
+	}
+
+	u.writeAudit(r, model.EventPasswordChanged, &acct.ID, &acct.ID, `{"via":"ui_self_service"}`)
+
+	csrfToken, _ := u.setCSRFCookies(w)
+	u.render(w, "password_change_result", ProfileData{
+		PageData: PageData{
+			CSRFToken: csrfToken,
+			ActorName: u.actorName(r),
+			Flash:     "Password updated successfully. Other active sessions have been revoked.",
+		},
+	})
+}