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/config.py

@@ -3,7 +3,7 @@ from pydantic_settings import BaseSettings, SettingsConfigDict
 
 
 class Settings(BaseSettings):
-    anthropic_api_key: str | None = None  # not used — claude CLI handles auth
+    anthropic_api_key: str | None = None  # not used — configure via model registry
 
     # Google OAuth — "Sign in with Google" for all users
     # Create credentials at console.cloud.google.com → APIs & Services → Credentials
@@ -38,7 +38,6 @@ class Settings(BaseSettings):
     default_model: str = "claude-sonnet-4-6"
     default_tier: int = 2
     max_history_messages: int = 40  # rolling window — 20 turns (user + assistant)
-    primary_backend: str = "claude"  # "claude" | "local" — gemini CLI removed June 2026
 
     # Local model backend — OpenAI-compatible API (Open WebUI / Ollama)
     # Set LOCAL_API_URL in .env to enable; leave blank to disable
@@ -46,9 +45,6 @@ class Settings(BaseSettings):
     local_api_key: str = ""            # sk-... from Open WebUI → Settings → Account → API Keys
     local_model: str = ""              # workspace or model name, e.g. test-agent-simple
 
-    # Per-backend timeouts in seconds
-    timeout_claude: int = 60
-    timeout_gemini: int = 120   # frequently slow under load
     timeout_local: int = 300    # local models may need to load first
 
     # Auto-distillation schedule — override in .env
@@ -66,14 +62,13 @@ class Settings(BaseSettings):
     distill_backend_long: str = ""
 
     # Model registry: default backend type per role when user registry has no entry.
-    # Values: "claude_cli" | "gemini_cli" | "gemini_api" (builtin IDs)
-    # Override in .env: ROLE_CHAT=claude_cli  ROLE_DISTILL=gemini_api  etc.
-    role_chat: str = "claude_cli"
-    role_orchestrator: str = "gemini_api"
-    role_distill: str = "claude_cli"
-    role_janitor: str = "claude_cli"   # assign a cheap/fast model: Haiku 4.5, local Gemma E4B
-    role_coder: str = "claude_cli"
-    role_research: str = "gemini_api"
+    # All roles must be configured via /settings/models — no built-in fallback.
+    role_chat: str = ""
+    role_orchestrator: str = ""
+    role_distill: str = ""
+    role_janitor: str = ""
+    role_coder: str = ""
+    role_research: str = ""
 
     # Comma-separated list of standard roles shown in the model settings UI.
     # Add custom roles here to extend the UI without code changes.
@@ -122,8 +117,8 @@ class Settings(BaseSettings):
         return [r.strip() for r in self.defined_roles.split(",") if r.strip()]
 
     def get_role_default(self, role: str) -> str:
-        """Return the .env default backend type for a role (e.g. 'claude_cli')."""
-        return getattr(self, f"role_{role.replace('-', '_')}", "claude_cli")
+        """Return the .env default backend type for a role, or '' if unconfigured."""
+        return getattr(self, f"role_{role.replace('-', '_')}", "")
 
     def home_root(self) -> Path:
         """Resolve home_dir relative to this file's location if not absolute."""