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/routers/local_llm.py

@@ -744,6 +744,53 @@ async def remove_custom_role_route(
     return RedirectResponse("/settings/models#roles", status_code=303)
 
 
+@router.post("/api/models/{model_id}/edit")
+async def edit_model_ajax(
+    request:                 Request,
+    model_id:                str,
+    mtype:                   str = Form(""),
+    label:                   str = Form(""),
+    model_name:              str = Form(""),
+    context_k:               int = Form(0),
+    max_rounds:              int = Form(0),
+    tools:                   int = Form(1),
+    tags:                    str = Form(""),
+    reasoning_budget_tokens: int = Form(0),
+    host_id:                 str = Form(""),
+    account_id:              str = Form(""),
+    credential_id:           str = Form("cli"),
+) -> JSONResponse:
+    """AJAX: edit a model entry. Returns JSON {ok, label, model_name} on success."""
+    username = _get_user(request)
+    if not username:
+        return JSONResponse({"error": "Not authenticated"}, status_code=401)
+    if not model_name.strip():
+        return JSONResponse({"error": "Model name is required."}, status_code=400)
+    tag_list          = [t.strip() for t in tags.split(",") if t.strip()]
+    max_rounds_       = max_rounds or None
+    tools_bool        = tools != 0
+    reasoning_budget_ = reasoning_budget_tokens or None
+    if mtype == "local_openai":
+        if not host_id.strip():
+            return JSONResponse({"error": "Select a host for this model."}, status_code=400)
+        reg.save_model(username, model_id, host_id, label, model_name, context_k, tag_list,
+                       max_rounds=max_rounds_, tools=tools_bool,
+                       reasoning_budget_tokens=reasoning_budget_)
+    elif mtype == "gemini_api":
+        reg.save_cloud_model(username, model_id, "google", model_name, label,
+                             account_id=account_id or None, context_k=context_k, tags=tag_list,
+                             max_rounds=max_rounds_, tools=tools_bool)
+    elif mtype in ("claude_cli", "anthropic_api"):
+        reg.save_cloud_model(username, model_id, "anthropic", model_name, label,
+                             credential_id=credential_id or "cli", context_k=context_k, tags=tag_list,
+                             max_rounds=max_rounds_, tools=tools_bool)
+    else:
+        return JSONResponse({"error": f"Unknown model type: {mtype}"}, status_code=400)
+    display = label.strip() or model_name.strip()
+    logger.info("model edited (ajax): %s / %s (%s)", username, display, mtype)
+    return JSONResponse({"ok": True, "label": display, "model_name": model_name.strip()})
+
+
 @router.post("/api/models/role")
 async def set_role(request: Request) -> JSONResponse:
     """AJAX: assign a model to a role priority slot.