feat: pre-computed state store and async ACME issuance (fixes timeout mismatch)

- Add lib/state.py: in-memory state store with subsystem collectors
  (firewall, dnsmasq, nginx, acme, wireguard)
- Refactor all handlers: read from state on GET, call refresh_state()
  after mutations instead of invoking subprocesses per request
- daemon/server.py: add refresh_state(), /status/all, /status/refresh;
  populate state at startup
- webui/api/certs.py: async step-by-step ACME issuance (validate,
  issue with request_id, poll status) replacing blocking endpoint
- webui/server.py: render pages from state instead of direct lib calls
- Update templates, JS for async cert issuance with polling UI
- Update tests for state-based mocking; add test_state.py
- Fix SIM105 lint issue (contextlib.suppress)
- Add TODO.md with certificate issuance issue tracking

Resolves: WebUI 30s timeout freeze during cert issuance (Problem 1)

webui/templates/certs.html

@@ -7,7 +7,7 @@
         <h1>Certificates</h1>
         <div class="subtitle">SSL/TLS certificate management</div>
     </div>
-    <button class="btn btn-primary" onclick="openModal('issue-cert-modal')">+ Issue New Certificate</button>
+    <button class="btn btn-primary" onclick="resetIssueWizard(); openModal('issue-cert-modal')">+ Issue New Certificate</button>
 </div>
 
 <div class="card">
@@ -53,24 +53,42 @@
     </table>
 </div>
 
-<!-- Issue Certificate Modal -->
-<div class="modal-overlay" id="issue-cert-modal" onclick="if(event.target===this) closeModal('issue-cert-modal')">
-    <div class="modal">
+<!-- Issue Certificate Modal — Phase 1: Validate -->
+<div class="modal-overlay" id="issue-cert-modal" onclick="if(event.target===this) closeIssueWizard()">
+    <div class="modal" style="min-width:480px;">
         <h2>Issue New Certificate</h2>
-                <form hx-post="/api/certs/issue" hx-encoding="json" hx-swap="none" hx-on::after-request="if(evt.detail.successful){ closeModal('issue-cert-modal'); refreshTable('/api/certs/list', document.getElementById('cert-rows'), renderCerts); showSuccessToast('Certificate issuance started'); }">
+
+        <!-- Phase 1: Input + Pre-flight Checks -->
+        <div id="cert-wizard-input">
             <div class="form-group">
                 <label for="cert-domain">Domain</label>
-                <input type="text" id="cert-domain" name="domain" placeholder="example.com" required>
+                <input type="text" id="cert-domain" placeholder="example.com" required>
             </div>
             <div class="form-group">
                 <label for="cert-email">Contact Email</label>
-                <input type="email" id="cert-email" name="email" placeholder="admin@example.com" value="{{ (email or '') | e }}">
+                <input type="email" id="cert-email" placeholder="admin@example.com" value="{{ (email or '') | e }}">
             </div>
+
+            <!-- Pre-flight validation results (shown after Check) -->
+            <div id="cert-check-results" style="display:none;">
+                <div class="section-title" style="margin-top:16px;">Pre-flight Checks</div>
+                <div id="cert-checks-list"></div>
+            </div>
+
             <div class="modal-actions">
-                <button type="button" class="btn btn-outline" onclick="closeModal('issue-cert-modal')">Cancel</button>
-                <button type="submit" class="btn btn-primary">Issue</button>
+                <button type="button" class="btn btn-outline" onclick="closeIssueWizard()">Cancel</button>
+                <button type="button" id="cert-check-btn" class="btn btn-primary" onclick="validateCertIssue()">Check</button>
+                <button type="button" id="cert-issue-btn" class="btn btn-primary" style="display:none;" onclick="startCertIssue()">Issue</button>
             </div>
-        </form>
+        </div>
+
+        <!-- Phase 2: Step progress -->
+        <div id="cert-wizard-progress" style="display:none;">
+            <div id="cert-steps-list"></div>
+            <div class="modal-actions">
+                <button type="button" class="btn btn-outline" id="cert-close-progress" style="display:none;" onclick="closeIssueWizard(); refreshTable('/api/certs/list', document.getElementById('cert-rows'), renderCerts);">Done</button>
+            </div>
+        </div>
     </div>
 </div>
 {% endblock %}