Claude Code engine, image viewer, colour tags, checks per turn and more

- Claude Code as an engine: chats on a "claude-code/<alias>" model run through
  the claude CLI (stream-json); tool approvals go through our permission
  system. Sign in from the web UI (URL + pasted code), CLI version and update
  from Settings; the Docker image contains the CLI.
- Small models (8k context) for side tasks: input is cut to the model's
  context window; one-line chat status, "What does this do?" on approvals,
  "Plan as automation" (job draft from a chat).
- Mobile: top bar no longer widens the page, image viewer (zoom, swipe, mark
  up, use in message), jump to previous own message, message menu, time under
  every message.
- Approvals: push actions (allow/reject), "always allow in this project"
  (never for dangerous commands) with revoke.
- Per turn: changed files with diffs and rollback; project check command with
  a green/red badge and "let the agent fix it".
- Colour tags for chats in the colours of the active theme.
- Project defaults for new chats, project page (timeline), offline queue.

Tested in a throwaway container with a mock model (8k small model): 26 API
checks passed (permissions, diffs, checks, defaults, job draft, side-task
budget, Claude Code status/login URL, unsigned-in chat).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

server/src/provider/mod.rs

@@ -61,9 +61,21 @@ impl Registry {
                 ProviderEntry { name: name.clone(), provider, models },
             );
         }
+        // Claude Code (the CLI's own agent) appears as a model list when it is installed.
+        if !providers.contains_key(crate::claude_code::PROVIDER) && crate::claude_code::binary().is_some() {
+            providers.insert(
+                crate::claude_code::PROVIDER.to_string(),
+                ProviderEntry { name: crate::claude_code::PROVIDER.to_string(), provider: Arc::new(crate::claude_code::Marker), models: crate::claude_code::models() },
+            );
+        }
         Self { providers, limits }
     }
 
+    /// First model of any provider but `skip`.
+    pub fn first_model_excluding(&self, skip: &str) -> Option<String> {
+        self.providers.values().filter(|e| e.name != skip).find_map(|e| e.models.first().map(|m| format!("{}/{}", e.name, m.id)))
+    }
+
     /// Wait for a free slot on the model and its provider. Always acquired in the
     /// same order (model, then provider), so concurrent requests cannot deadlock.
     pub async fn acquire(&self, spec: &str) -> Slot {