T10.4: remove the local password path entirely

Real deletion (D15's 'full replacement'), not a toggle. Okta is now the only
credential this app accepts anywhere.

Backend:
- server/models.py: drop User.password_hash.
- server/alembic/versions/1d60a608bb51_...: matching migration (op.drop_column,
  same plain-drop precedent as project_role/locked_until/etc.; downgrade re-adds
  it with server_default='').
- server/auth.py: remove hash_password/verify_password/password_problem/
  MIN_PASSWORD_LEN/_COMMON_PASSWORDS, create_reset_token/decode_reset_token/
  RESET_MINUTES, the bcrypt import. Roles/tokens/cookies/get_current_user
  untouched.
- server/app.py: remove login(), the whole self-service reset-password block
  (forgot-password/reset-available/reset-password), and change_password()
  (POST /api/auth/password). Rework create_user() to drop the password field
  (with a docstring note: the username must exactly match the eventual Okta
  identity claim, or a later sign-in provisions a second account instead of
  matching this one). Remove admin_reset_password() outright - nothing left to
  reset. Fixes a bug this task's own predecessor left behind: okta_callback()'s
  JIT provisioning (T10.3) was still setting password_hash="", which would have
  raised TypeError the moment the column was actually dropped.

Admin bootstrap (D16): server/manage_users.py moves from creating accounts
(create/create-admin/reset-password, all password-based) to a single 'promote
<username> --role <role>' command that changes the role on a row Okta's JIT
provisioning already created - the documented path for naming the first admin.
list/disable/enable unchanged.

Frontend: html/users.js drops the password field and validation from
createUser(), removes resetPw() and its button (nothing left to reset).
html/users.html drops the #nu-password input, adds a tooltip on username
explaining the exact-match-to-Okta requirement. html/auth-guard.js removes the
wpChangePassword dialog; html/wp-sidenav.js removes the 'Password' menu item
that opened it.

Tests: tests/browser_check.py and tests/launcher_check.py stop hashing a
password to seed fixture rows (and the --keep-server hint now prints a
ready-to-use cookie-setting snippet instead of a dead username/password).
tests/pipeline_check.py and tests/token_check.py drop an unused PW import.
tests/console_dialogs_check.py: the admin password-reset dialog it drove no
longer exists, so that scenario is removed - the prompt-with-validate() UI
pattern it exercised is still covered via creator_dialogs_check.py's
wp-creation-app.js call sites, noted in this file's docstring so the coverage
move isn't silent. tests/url_state_check.py: the "next= survives a real sign-in
via login" scenario is explicitly marked SKIPPED (not deleted, not faked) -
that promise is specific to the login FORM this task removed and can't be
honestly re-proven until T10.5 rebuilds it as an Okta redirect; a minted-token
cookie now stands in as setup only, so scenarios 3-6 in that file still get a
signed-in page to run against.

server/smoketest.py and server/seed_demo.py: switched from POST /api/auth/login
to minting a session the same way okta_callback() does (auth.create_token(),
seeded into the cookie jar) rather than waiting on T10.7. This is a real
operational change, documented in both files' own AUTHENTICATION sections: they
now need to run where AUTH_SECRET_KEY and the database match the target
server's (inside the api container, or local dev) - they can no longer sign in
to an arbitrary remote URL from an unrelated workstation, because Okta requires
a real browser and these are stdlib scripts. The account must already exist;
neither script creates or promotes one.

server/requirements.txt: bcrypt dropped, nothing imports it anymore.

Verified: full Alembic chain (baseline through this migration) upgrades and
downgrades cleanly against a throwaway SQLite DB. okta_callback() JIT
provisioning re-tested against the post-migration schema (would have thrown
before the password_hash="" fix above). create_user() verified via a live HTTP
call with no password field. manage_users.py promote verified end to end
(seed a JIT-shaped row at project_user, promote to admin, list). smoketest.py
and seed_demo.py both run to completion against a live uvicorn instance using
the new minted-session path - 25/25 checks, including logout actually
invalidating the session (proving the cookie-jar seeding didn't just fake the
sign-in, it preserved the real expiry mechanics).

wave-10.md T10.4 / D15 / D16

html/users.js

@@ -183,11 +183,9 @@ function managerRow(u){
     : projRoleReadonly(u, can, why);
 
   const actions = [];
-  if(can && !me) actions.push('<button class="mini" onclick="resetPw(\''+uid+'\',\''+uname+'\')">Reset password</button>');
   if(can && !me) actions.push('<button class="mini" onclick="toggleActive(\''+uid+'\','+(!u.is_active)+')">'+
     (u.is_active?'Disable':'Enable')+'</button>');
   if(can && !me) actions.push('<button class="mini danger" onclick="deleteUser(\''+uid+'\',\''+uname+'\')">Delete</button>');
-  if(me) actions.push('<button class="mini" disabled title="Use the Password link in the top bar to change your own">—</button>');
   if(!can && !me) actions.push('<span class="note" style="margin:0" title="'+uesc(why)+'">read-only</span>');
 
   return '<tr'+(can||me ? '' : ' class="is-locked"')+'>'+
@@ -254,19 +252,6 @@ function projAccessCell(u){
 // ── row actions ───────────────────────────────────────────────────────────────
 // Each one reloads on failure so a control can never sit there showing a value the
 // server refused.
-async function resetPw(id, username){
-  // The min-12 rule was stated in the prompt label and enforced only by the
-  // server round-trip; the kit's validate() answers AT the input instead.
-  const pw = await wpPromptDialog({title:'Reset password',
-    message:'Set a new password for "'+username+'". Their existing sessions are signed out.',
-    label:'New password (min 12 characters)',
-    validate:v => (v && v.length >= 12) ? '' : 'At least 12 characters.'});
-  if(pw === null) return;
-  const { status, json } = await api('POST','/api/auth/users/'+id+'/password',{new_password:pw});
-  if(status === 200) toast('Password reset for '+username+'. Their existing sessions are signed out.');
-  else wpAlertDialog({title:'Reset failed', message:'Could not reset the password: '+apiError(status, json)});
-}
-
 async function toggleActive(id, makeActive){
   const { status, json } = await api('POST','/api/auth/users/'+id+'/active',{is_active:makeActive});
   if(status === 200) loadUsers();
@@ -344,25 +329,27 @@ function renderCreateForm(){
 async function createUser(){
   const msg = document.getElementById('users-create-msg');
   const val = id => (document.getElementById(id)||{}).value || '';
+  // The username entered here MUST match what Okta's identity claim will send for
+  // this person exactly — this creates the account ahead of their first sign-in,
+  // and that's how a later Okta sign-in finds this row instead of provisioning a
+  // second one. See create_user()'s docstring in server/app.py.
   const username = val('nu-username').trim();
-  const password = val('nu-password');
   const project_ids = [...document.querySelectorAll('#nu-project-list input[type=checkbox]:checked')]
     .map(c => c.value);
   const say = (color, text) => { msg.style.color = color; msg.textContent = text; };
   if(!username){ say('var(--red)','Username is required.'); return; }
-  if(password.length < 12){ say('var(--red)','Password must be at least 12 characters.'); return; }
   if(_scope.scope !== 'all' && !project_ids.length){
     say('var(--red)','Pick at least one project — you administer users per project.'); return;
   }
   say('var(--muted)','Creating…');
   const { status, json } = await api('POST','/api/auth/users',{
-    username, password, project_ids,
+    username, project_ids,
     full_name: val('nu-fullname').trim(), email: val('nu-email').trim(),
     role: val('nu-role'), project_role: val('nu-project-role'),
   });
   if(status === 200){
     say('var(--green)','✓ Created '+username+'.');
-    ['nu-username','nu-fullname','nu-email','nu-password'].forEach(id => document.getElementById(id).value = '');
+    ['nu-username','nu-fullname','nu-email'].forEach(id => document.getElementById(id).value = '');
     loadUsers();
   } else {
     say('var(--red)','✕ '+apiError(status, json, 'Could not create the account'));