feat(dashboard): wire skills autocomplete configuration to session cards

Connect the skills enumeration API to session card input fields for
slash command autocomplete:

App.js:
- Add skillsConfig state for Claude and Codex skill configs
- Fetch skills for both agent types on mount using Promise.all
- Pass agent-appropriate autocompleteConfig to each SessionCard

SessionCard.js:
- Accept autocompleteConfig prop and forward to SimpleInput
- Move context usage display from header to footer status bar for
  better information hierarchy (activity indicator + context together)

SimpleInput.js:
- Fix autocomplete dropdown padding (py-2 -> py-1.5)
- Fix font inheritance (add font-mono to skill name)
- Fix description tooltip whitespace handling (add font-sans,
  whitespace-normal)

SpawnModal.js:
- Add SPAWN_TIMEOUT_MS (2x default) to handle pending spawn registry
  wait time plus session file confirmation polling

AgentActivityIndicator.js:
- Minor styling refinement for status display

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

dashboard/components/SpawnModal.js

@@ -1,5 +1,9 @@
 import { html, useState, useEffect, useCallback, useRef } from '../lib/preact.js';
-import { API_PROJECTS, API_SPAWN, fetchWithTimeout } from '../utils/api.js';
+import { API_PROJECTS, API_SPAWN, fetchWithTimeout, API_TIMEOUT_MS } from '../utils/api.js';
+
+// Spawn needs longer timeout: pending spawn registry requires discovery cycle to run,
+// plus server polls for session file confirmation
+const SPAWN_TIMEOUT_MS = API_TIMEOUT_MS * 2;
 
 export function SpawnModal({ isOpen, onClose, onSpawn, currentProject }) {
   const [projects, setProjects] = useState([]);
@@ -95,7 +99,7 @@ export function SpawnModal({ isOpen, onClose, onSpawn, currentProject }) {
           'Authorization': `Bearer ${window.AMC_AUTH_TOKEN}`,
         },
         body: JSON.stringify({ project, agent_type: agentType }),
-      });
+      }, SPAWN_TIMEOUT_MS);
       const data = await response.json();
 
       if (data.ok) {