fix: HERMES_WEBUI_SKIP_ONBOARDING unconditional + guard against config writes + 10 skipped tests fixed — v0.50.65

Fixes two SKIP_ONBOARDING bugs and eliminates 10 permanently-skipped integration tests.

- SKIP_ONBOARDING=1 now honoured unconditionally (no longer gated on chat_ready)
- apply_onboarding_setup refuses to write config/env files when SKIP_ONBOARDING is set
- TestMediaEndpointIntegration (6) and TestOnboardingGateIntegration (4): collection-time
  skip guards removed; server reachability checked at runtime with fail() not skip()

Tests: 1327 passed, 0 skipped.

Admin merge — self-built PR, Nathan authorized full merge process in session.

static/index.html

@@ -553,7 +553,7 @@
                 <div class="settings-section-title">System</div>
                 <div class="settings-section-meta">Instance version and access controls.</div>
               </div>
-              <span class="settings-version-badge">v0.50.64</span>
+              <span class="settings-version-badge">v0.50.65</span>
             </div>
             <div class="settings-field" style="border-top:1px solid var(--border);padding-top:12px;margin-top:8px">
               <label for="settingsPassword" data-i18n="settings_label_password">Access Password</label>