feat(signup+admin): aliniere formular signup la landing + plan cerut, GDPR, control tier/trial in panou

Signup:
- /signup aliniat ca format la formularul din landing (campuri, etichete,
  placeholder-uri, select plan, checkbox GDPR, buton). Eticheta `name` = "Companie"
  (corecta: backendul salveaza nume de firma), uniform si in landing.
- Consimtamant GDPR validat server-side (functional, nu doar client-side) + salvat
  cu marca temporala (accounts.consent_at).
- Plan ales la signup salvat in accounts.requested_plan (intentie, NU drept): tier
  ramane sursa de adevar pentru gate-ul API; coloana pregateste integrarea platilor.
- landing: valorile `plan` = coduri tier (free/standard/pro/premium), data-plan
  sincronizat pe butoanele de pret; checkbox consimtamant primeste name.

Schema/DB:
- accounts: coloane noi requested_plan + consent_at (cu migrare aditiva in db.py).

Panou admin:
- Coloane noi: Plan curent (plan EFECTIV acum + zile trial ramase) si Plan cerut.
- Buton "Aplica" (POST /admin/set-tier): aloca plan real si INCHEIE trial-ul
  (efect imediat; altfel trial-ul Pro universal de 30z masca alegerea).
- Control "Trial Pro N zile" (POST /admin/set-trial via accounts.set_trial):
  acorda/prelungeste trial fara a schimba tier-ul de baza.

Teste: signup (consent obligatoriu, requested_plan persistat, tier ramane free),
panou admin (set-tier incheie trial, free opreste Pro imediat, set-trial, validari
+ CSRF). Call-site-urile existente POST /signup actualizate cu consent.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/web/templates/admin.html

@@ -10,6 +10,9 @@
   'delete':   ('Sterge',    '/admin/delete', 'danger')
 } %}
 
+{# Tier-uri selectabile in panou (cod, eticheta). Aliniat cu app/plans.py#PLANS. #}
+{% set TIERS = [('free', 'Gratuit'), ('standard', 'Standard'), ('pro', 'Pro'), ('premium', 'Premium')] %}
+
 {% macro lifecycle_block(title, rows, block_id, bulk_verbs, row_verbs) %}
 <div class="card">
   <h3 style="margin-top:0;">{{ title }} ({{ rows|length }})</h3>
@@ -34,7 +37,7 @@
       <thead><tr>
         <th style="width:28px;"><input type="checkbox" class="master-check" data-block="{{ block_id }}"
                    aria-label="Selecteaza tot"></th>
-        <th>ID</th><th>Companie</th><th>CUI</th><th>Email</th><th>Stare</th><th>Inregistrat</th><th>Actiuni</th>
+        <th>ID</th><th>Companie</th><th>CUI</th><th>Email</th><th>Plan curent</th><th>Plan cerut</th><th>Stare</th><th>Inregistrat</th><th>Actiuni</th>
       </tr></thead>
       <tbody>
         {% for acct in rows %}
@@ -46,6 +49,45 @@
           <td>{{ acct.name }}</td>
           <td class="muted">{{ acct.cui or "—" }}</td>
           <td>{{ acct.email or "—" }}</td>
+          <td style="white-space:nowrap;">
+            {# Plan EFECTIV acum (prominent): trial Pro activ ridica free->pro. #}
+            <div style="margin-bottom:5px;">
+              <span class="pill" style="font-weight:600;">{{ acct.tier_efectiv_label }}</span>
+              {% if acct.trial_activ %}
+              <span class="muted" style="font-size:11px;">
+                trial{% if acct.trial_zile %} · {{ acct.trial_zile }} {{ 'zi' if acct.trial_zile == 1 else 'zile' }} ramase{% endif %}
+                → apoi {{ acct.tier_label }}
+              </span>
+              {% endif %}
+            </div>
+            {# Schimbare plan inline: select tier de baza + Aplica. Form propriu (nu imbricat in bulk-form).
+               Aplica INCHEIE trial-ul si seteaza planul ales ca real, cu efect imediat. #}
+            <form method="post" action="/admin/set-tier" class="tier-form"
+                  style="display:flex;align-items:center;gap:6px;">
+              <input type="hidden" name="csrf_token" value="{{ csrf_token }}">
+              <input type="hidden" name="account_id" value="{{ acct.id }}">
+              <select name="tier" aria-label="Plan pentru {{ acct.name }}"
+                      style="padding:4px 8px;min-height:32px;max-width:130px;">
+                {% for code, label in TIERS %}
+                <option value="{{ code }}"{% if acct.tier == code %} selected{% endif %}>{{ label }}</option>
+                {% endfor %}
+              </select>
+              <button type="submit" class="btn-sm"
+                      title="Aplica planul ales ca plan real (incheie trial-ul daca e activ)">Aplica</button>
+            </form>
+            {# Acorda/prelungeste trial Pro de N zile, fara a schimba tier-ul de baza. #}
+            <form method="post" action="/admin/set-trial" class="trial-form"
+                  style="display:flex;align-items:center;gap:6px;margin-top:5px;">
+              <input type="hidden" name="csrf_token" value="{{ csrf_token }}">
+              <input type="hidden" name="account_id" value="{{ acct.id }}">
+              <input type="number" name="trial_days" value="30" min="1" max="3650"
+                     aria-label="Zile trial Pro pentru {{ acct.name }}"
+                     style="padding:4px 8px;min-height:32px;width:64px;">
+              <button type="submit" class="btn-sm"
+                      title="Acorda/prelungeste trial Pro de la acum (nu schimba tier-ul de baza)">Trial Pro</button>
+            </form>
+          </td>
+          <td class="muted">{{ acct.requested_plan_label }}</td>
           <td><span class="pill">{{ acct.status }}</span></td>
           <td class="muted">{{ acct.created_at or "—" }}</td>
           <td style="white-space:nowrap;">