feat: SSH dev routing, model registry UX, chat input toolbar, doc sync

Backend / infrastructure:
- cortex/tools/_projects.py (new): shared project alias registry with ssh_host
  for workstation projects (aether_api, aether_frontend, aether_container)
- cortex/tools/git.py: all git tools route to workstation via SSH when ssh_host set
- cortex/tools/aider.py: aider_run SSH-routes to workstation using bash -l -c
- cortex/routers/local_llm.py: POST /api/models/{id}/edit AJAX endpoint — save
  model edits without page reload or tab reset; returns JSON {ok, label, model_name}
- cortex/llm_client.py: remove Gemini CLI and Claude CLI backends; clean up
  fallback chain and process group tracking (continuation of Gemini CLI removal)
- cortex/routers/auth.py: strip Claude/Gemini CLI auth status checks (CLI removed)
- cortex/routers/chat.py: remove legacy claude/gemini backend fields
- cortex/config.py: clean up CLI-related settings
- cortex/main.py: remove CLI lifecycle hooks

UI:
- cortex/static/local_llm.html: model edit forms now save via fetch() + toast;
  stay on Models tab; update row header label in place on success
- cortex/static/index.html: restructure input area to column layout — textarea
  above, compact toolbar below (Chat/Tools/Attach + Send); fixes dead space at
  M/L/XL sizes; context panel "Role" → "Model" section label
- cortex/static/style.css: column input-area layout; #input-toolbar; flex:1 →
  width:100% on textarea (fixes scrollHeight in column flex context); compact
  send/stop button padding
- cortex/static/app.js: add XL (720px) to height cycle; default M (240px)

Docs:
- cortex/static/HELP.md: S/M/L → S/M/L/XL; add Rebuild to distill table; fix
  "Role selector" references (no such UI); fix "your active role" → Chat role;
  fix ⚡ toggle description; Model Registry section cleanup
- documentation/ARCH__BACKENDS.md: reflect CLI removal, current backend state

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cortex/static/local_llm.html

@@ -982,6 +982,42 @@
       });
     });
 
+    // ── Model edit: AJAX save (stay on Models tab) ────────────────────────────
+    document.querySelectorAll('.model-edit-form').forEach(form => {
+      form.addEventListener('submit', async e => {
+        e.preventDefault();
+        const id      = form.id.replace('edit-form-', '');
+        const saveBtn = form.querySelector('button[type="submit"]');
+        saveBtn.disabled = true;
+        try {
+          const res  = await fetch(`/api/models/${id}/edit`, {method: 'POST', body: new FormData(form)});
+          const data = await res.json();
+          if (data.ok) {
+            // Update the row header label in place
+            const row = document.getElementById('model-' + id);
+            if (row && data.label) {
+              const labelEl = row.querySelector('.model-label');
+              if (labelEl) labelEl.textContent = data.label;
+            }
+            if (row && data.model_name) {
+              const nameEl = row.querySelector('.model-name');
+              if (nameEl) nameEl.textContent = data.model_name;
+            }
+            // Close the edit panel
+            form.style.display = 'none';
+            document.querySelector(`.model-edit-btn[data-id="${id}"]`).textContent = 'Edit';
+            showToast('Model saved');
+          } else {
+            showToast(data.error || 'Save failed', true);
+          }
+        } catch (err) {
+          showToast(err.message, true);
+        } finally {
+          saveBtn.disabled = false;
+        }
+      });
+    });
+
     // ── Edit form: fetch from host ────────────────────────────────────────────
     document.querySelectorAll('.edit-fetch-btn').forEach(btn => {
       btn.addEventListener('click', async () => {