feat: add Clear History button to delete all consumed instructions

- Backend: instruction_service.clear_consumed() bulk-deletes consumed rows
- Backend: DELETE /api/instructions/consumed route (preserves pending)
- Frontend: Clear button in consumed panel header (hidden when empty)
- Frontend: SSE handler for history.cleared event - instant UI update
- Frontend: api.clearConsumed() fetch wrapper

app/api/routes_instructions.py

@@ -57,6 +57,14 @@ def update_instruction(instruction_id: str, body: UpdateInstructionRequest):
     return InstructionCreateResponse(item=item)
 
 
+@router.delete("/consumed", status_code=200)
+def clear_consumed_instructions():
+    """Delete all consumed instructions. Pending instructions are never affected."""
+    count = instruction_service.clear_consumed()
+    event_service.broadcast("history.cleared", {"count": count})
+    return {"cleared": count}
+
+
 @router.delete("/{instruction_id}", status_code=204)
 def delete_instruction(instruction_id: str):
     try:

app/services/instruction_service.py

@@ -168,6 +168,19 @@ def delete_instruction(instruction_id: str) -> None:
     logger.info("Instruction deleted id=%s", instruction_id)
 
 
+def clear_consumed() -> int:
+    """Delete all consumed instructions. Returns the number of rows deleted."""
+    with get_write_conn() as conn:
+        row = conn.execute(
+            "SELECT COUNT(*) FROM instructions WHERE status = 'consumed'"
+        ).fetchone()
+        count = row[0] if row else 0
+        conn.execute("DELETE FROM instructions WHERE status = 'consumed'")
+
+    logger.info("Consumed instructions cleared count=%d", count)
+    return count
+
+
 def consume_next(agent_id: str = "unknown") -> Optional[InstructionItem]:
     """
     Atomically claim and return the next pending instruction.

static/index.html

@@ -111,7 +111,13 @@
           <svg class="icon icon--sm" viewBox="0 0 24 24"><polyline points="9 11 12 14 22 4"/><path d="M21 12v7a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11"/></svg>
           Consumed
         </span>
+        <div style="display:flex;align-items:center;gap:var(--space-2)">
           <span id="consumed-badge" class="badge badge--muted">0</span>
+          <button id="clear-history-btn" class="btn btn--ghost btn--sm" title="Clear all consumed instructions" style="display:none">
+            <svg class="icon icon--sm" viewBox="0 0 24 24"><polyline points="3 6 5 6 21 6"/><path d="M19 6l-1 14a2 2 0 0 1-2 2H8a2 2 0 0 1-2-2L5 6"/><path d="M10 11v6"/><path d="M14 11v6"/><path d="M9 6V4a1 1 0 0 1 1-1h4a1 1 0 0 1 1 1v2"/></svg>
+            Clear
+          </button>
+        </div>
       </div>
       <div class="panel-body panel-body--flush">
         <div id="consumed-list">
@@ -151,9 +157,9 @@
       <div class="panel-body">
         <form id="config-form">
           <div class="config-field">
-            <label class="config-label" for="cfg-wait">Min Wait (sec)</label>
+            <label class="config-label" for="cfg-wait">Wait (sec)</label>
             <input id="cfg-wait" class="input input--sm" type="number" min="0" max="300" value="10" />
-            <span class="config-hint">Server enforces this as the minimum wait before returning an empty response. Agent may request longer but never shorter.</span>
+            <span class="config-hint">How long the tool waits for a new instruction before returning an empty response. Set exclusively here — agents cannot override this.</span>
           </div>
           <div class="config-field">
             <label class="config-label" for="cfg-empty">Empty Response</label>

static/js/api.js

@@ -35,6 +35,7 @@ export const api = {
   createInstruction: (content)     => request('POST', '/api/instructions', { content }),
   updateInstruction: (id, content) => request('PATCH', `/api/instructions/${id}`, { content }),
   deleteInstruction: (id)          => request('DELETE', `/api/instructions/${id}`),
+  clearConsumed: ()                => request('DELETE', '/api/instructions/consumed'),
 
   // Config
   getConfig: ()                   => request('GET', '/api/config'),

static/js/events.js

@@ -104,6 +104,11 @@ function _handleEvent(event) {
       }
       break;
     }
+    case 'history.cleared': {
+      const next = (state.get('instructions') || []).filter(i => i.status !== 'consumed');
+      state.set('instructions', next);
+      break;
+    }
     case 'status.changed': {
       api.status().then(s => state.set('status', s)).catch(console.error);
       break;

static/js/instructions.js

@@ -166,6 +166,7 @@ export function initInstructions() {
   const pendingBadge   = document.getElementById('pending-badge');
   const consumedList   = document.getElementById('consumed-list');
   const consumedBadge  = document.getElementById('consumed-badge');
+  const clearHistoryBtn = document.getElementById('clear-history-btn');
 
   function render(instructions) {
     if (!instructions) return;
@@ -190,14 +191,30 @@ export function initInstructions() {
     consumedList.innerHTML = '';
     if (consumed.length === 0) {
       consumedList.innerHTML = `<div class="empty-state"><div class="empty-state__icon">◈</div>No consumed instructions yet</div>`;
+      clearHistoryBtn.style.display = 'none';
     } else {
       consumed.forEach(item => consumedList.appendChild(renderConsumedCard(item)));
+      clearHistoryBtn.style.display = '';
     }
     consumedBadge.textContent = consumed.length;
     consumedBadge.className   = `badge ${consumed.length > 0 ? 'badge--amber' : 'badge--muted'}`;
   }
 
   state.subscribe('instructions', render);
+
+  // Clear history button
+  clearHistoryBtn.addEventListener('click', async () => {
+    if (!confirm('Clear all consumed instruction history? This cannot be undone.')) return;
+    clearHistoryBtn.disabled = true;
+    try {
+      const res = await api.clearConsumed();
+      toast(`Cleared ${res.cleared} consumed instruction${res.cleared !== 1 ? 's' : ''}`, 'info');
+    } catch (e) {
+      toast(e.message, 'error');
+    } finally {
+      clearHistoryBtn.disabled = false;
+    }
+  });
 }
 
 // ── Composer ──────────────────────────────────────────────────────────────