feat(shell): dedicated System Analyst AI, no code execution, analyze system

- New ShellConvStore with persistent history (shell_conversation.json)
- 100k token limit — input grays out, must /clear to continue
- Commands limited to /clear and /help only
- Shell AI has NO tools — read-only analysis, never executes code
- "Analyste Système" panel with system analysis button
- System analysis uses Studio AI to write system_analysis.md,
  prepended as context on every conversation start
- Code blocks show "Copier" and "Terminal" buttons to copy or
  send code directly to the active terminal via WebSocket
- Token bar shows usage with warning at 80%

💘 Generated with Crush

Assisted-by: GLM-5.1 via Crush <crush@charm.land>

web/src/styles/global.css

@@ -393,11 +393,26 @@ input::placeholder { color: var(--text-disabled); }
 .connection-dot.off { background: var(--error); }
 
 .shell-ai-col { width: 320px; border-left: 1px solid var(--border); background: var(--bg-surface); display: flex; flex-direction: column; flex-shrink: 0; }
-.ai-panel-header { padding: 12px 16px; border-bottom: 1px solid var(--border); font-weight: 700; font-size: 13px; color: var(--accent); }
+.ai-panel-header { padding: 12px 16px; border-bottom: 1px solid var(--border); font-weight: 700; font-size: 13px; color: var(--accent); display: flex; align-items: center; justify-content: space-between; }
+.shell-analyze-btn {
+  display: flex; align-items: center; gap: 4px;
+  padding: 4px 10px; border-radius: var(--radius);
+  background: transparent; border: 1px solid var(--accent-dim);
+  color: var(--accent); font-size: 11px; font-weight: 600;
+  cursor: pointer; transition: all 0.15s;
+}
+.shell-analyze-btn:hover:not(:disabled) { background: var(--accent-bg); }
+.shell-analyze-btn:disabled { opacity: 0.4; cursor: not-allowed; }
+.shell-ai-token-bar { display: flex; align-items: center; gap: 8px; padding: 6px 12px; border-bottom: 1px solid var(--border); }
+.shell-ai-token-track { flex: 1; height: 3px; background: var(--bg-input); border-radius: 2px; overflow: hidden; }
+.shell-ai-token-fill { height: 100%; background: var(--accent); border-radius: 2px; transition: width 0.4s, background 0.3s; }
+.shell-ai-token-fill.warn { background: var(--warning); }
+.shell-ai-token-text { font-size: 10px; font-family: var(--font-mono); color: var(--text-tertiary); white-space: nowrap; }
 .ai-panel-messages { flex: 1; overflow-y: auto; padding: 12px; display: flex; flex-direction: column; gap: 8px; }
 .ai-message { padding: 8px 12px; border-radius: var(--radius); font-size: 13px; line-height: 1.5; word-break: break-word; }
-.ai-message.ai { background: var(--bg-card); border-left: 3px solid var(--accent); }
-.ai-message.user { background: var(--accent-bg); border-left: 3px solid var(--accent-muted); }
+.ai-message.assistant { background: var(--bg-card); border-left: 3px solid var(--accent); }
+.ai-message.system { background: var(--bg-elevated); border-left: 3px solid var(--info); font-style: italic; color: var(--text-tertiary); font-size: 12px; }
+.ai-message.assistant { background: var(--bg-card); border-left: 3px solid var(--accent); }
 .ai-message.thinking { background: var(--bg-elevated); border-left: 3px solid var(--info); font-style: italic; color: var(--text-tertiary); }
 .ai-message.tool { background: var(--bg-elevated); border-left: 3px solid var(--warning); }
 .ai-message.tool .tool-name { font-weight: 700; color: var(--warning); }
@@ -405,6 +420,31 @@ input::placeholder { color: var(--text-disabled); }
 .ai-panel-input { display: flex; gap: 6px; padding: 10px 12px; border-top: 1px solid var(--border); }
 .ai-panel-input input { flex: 1; font-size: 13px; padding: 6px 10px; }
 
+.shell-code-block {
+  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius);
+  margin: 8px 0 4px; overflow: hidden;
+}
+.shell-code-block pre {
+  padding: 10px 12px; font-family: var(--font-mono); font-size: 12px; line-height: 1.5;
+  overflow-x: auto; color: var(--text-primary); margin: 0;
+}
+.shell-code-lang {
+  padding: 3px 10px; font-size: 10px; font-weight: 600; color: var(--text-tertiary);
+  background: var(--bg-surface); border-bottom: 1px solid var(--border);
+  text-transform: uppercase; letter-spacing: 0.5px;
+}
+.shell-code-actions {
+  display: flex; border-top: 1px solid var(--border); background: var(--bg-surface);
+}
+.shell-code-actions button {
+  flex: 1; display: flex; align-items: center; justify-content: center; gap: 4px;
+  padding: 5px 0; background: transparent; border: none; border-right: 1px solid var(--border);
+  color: var(--text-tertiary); font-size: 11px; cursor: pointer; transition: all 0.1s;
+  font-family: var(--font-sans);
+}
+.shell-code-actions button:last-child { border-right: none; }
+.shell-code-actions button:hover { background: var(--accent-bg); color: var(--accent); }
+
 .shell-modal-overlay {
   position: fixed; inset: 0; background: rgba(0,0,0,0.6);
   display: flex; align-items: center; justify-content: center; z-index: 1000;
@@ -505,10 +545,24 @@ input::placeholder { color: var(--text-disabled); }
 .config-update-name { color: var(--text-primary); font-weight: 600; font-size: 13px; min-width: 100px; }
 .config-update-versions { color: var(--text-tertiary); font-size: 12px; font-family: var(--font-mono); }
 
-.config-skill-row { display: flex; align-items: center; gap: 10px; padding: 8px 0; border-bottom: 1px solid var(--border); font-size: 13px; }
-.config-skill-row:last-child { border-bottom: none; }
-.config-skill-name { color: var(--text-primary); font-weight: 600; min-width: 120px; }
-.config-skill-desc { color: var(--text-tertiary); flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.skill-tiles { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 12px; }
+.skill-tile { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; cursor: pointer; transition: border-color 0.15s; }
+.skill-tile:hover { border-color: var(--accent-dim); }
+.skill-tile-name { font-weight: 600; color: var(--text-primary); font-size: 14px; margin-bottom: 6px; }
+.skill-tile-desc { font-size: 12px; color: var(--text-tertiary); overflow: hidden; text-overflow: ellipsis; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
+.skill-tile-tags { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 10px; }
+.skill-detail-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.7); z-index: 50; display: flex; align-items: center; justify-content: center; }
+.skill-detail-panel { background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-lg); width: 90%; max-width: 600px; max-height: 80vh; display: flex; flex-direction: column; overflow: hidden; }
+.skill-detail-header { display: flex; align-items: center; justify-content: space-between; padding: 16px 20px; border-bottom: 1px solid var(--border); }
+.skill-detail-name { font-weight: 600; font-size: 16px; color: var(--text-primary); }
+.skill-detail-body { flex: 1; overflow-y: auto; padding: 20px; }
+.skill-detail-section { margin-bottom: 16px; }
+.skill-detail-label { font-size: 11px; font-weight: 700; color: var(--accent); text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 6px; }
+.skill-detail-meta { display: flex; gap: 8px; flex-wrap: wrap; }
+.skill-detail-content { font-family: var(--font-mono); font-size: 12px; color: var(--text-secondary); white-space: pre-wrap; background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 12px; line-height: 1.6; max-height: 300px; overflow-y: auto; }
+.skill-detail-deps { display: flex; flex-direction: column; gap: 6px; }
+.skill-detail-dep { font-size: 12px; color: var(--text-tertiary); display: flex; align-items: center; gap: 8px; }
+.skill-detail-dep .badge { font-size: 10px; }
 .chip-row { display: flex; gap: 8px; flex-wrap: wrap; }
 
 .config-toast {