Proxy fixes, streaming support, Admin-UI overhaul

Backend:
- Fix Content-Length mismatch by not forwarding client headers to Ollama
- Proxy /v1/chat/completions directly to Ollama's OpenAI-compatible endpoint
  (eliminates manual Ollama↔OpenAI format conversion, fixes tool use)
- Add streaming support via SSE passthrough
- Fix ollama_url /v1 suffix stripped on save
- Replace BaseHTTPMiddleware with FastAPI global dependency (fixes double logging)
- Add rotating usage log (8 KB, logs key name + model + token estimate + prompt preview)
- Add httpx timeout 300s
- Add activate and delete endpoints for API keys
- Return usage data (tokens/requests) in GET /api/api-keys

Frontend:
- Admin table: remove ID column, status as icon, icon-only action buttons with CSS tooltips
- Add activate + delete buttons; edit available for inactive keys too
- Quota columns: fixed equal width, progress bars with k-unit formatting
- Create form: structured layout matching edit form style
- Edit form: token inputs in k units (÷1000 display, ×1000 on save)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/styles.css

@@ -92,30 +92,37 @@ tr:hover {
 
 .create-form {
   display: flex;
-  flex-wrap: wrap;
-  gap: 10px;
+  flex-direction: column;
+  gap: 12px;
+}
+
+.create-form .edit-form {
+  margin-bottom: 0;
+}
+
+.create-name {
+  flex: 0 0 auto !important;
+}
+
+.create-name input {
+  width: 200px;
+}
+
+.create-date {
+  flex: 0 0 auto !important;
+}
+
+.create-date input[type="date"] {
+  width: 150px;
+}
+
+.create-btn-wrap {
+  flex: 0 0 auto;
+  display: flex;
   align-items: flex-end;
 }
 
-.create-form input {
-  padding: 8px 10px;
-  border: 1px solid #ccc;
-  border-radius: 4px;
-  font-size: 14px;
-  flex: 1 1 160px;
-}
-
-.create-form button {
-  padding: 8px 20px;
-  background: #27ae60;
-  color: white;
-  border: none;
-  border-radius: 4px;
-  cursor: pointer;
-  font-size: 14px;
-}
-
-.create-form button:disabled {
+.create-form .btn-save:disabled {
   opacity: 0.6;
   cursor: not-allowed;
 }
@@ -218,3 +225,198 @@ tr:hover {
   color: #999;
   font-size: 12px;
 }
+
+/* Quota progress bars */
+.th-quota {
+  width: 90px;
+}
+
+.quota-cell {
+  width: 100%;
+}
+
+.quota-label {
+  font-size: 12px;
+  color: #555;
+  white-space: nowrap;
+}
+
+.quota-unlimited {
+  color: #aaa;
+  font-size: 14px;
+}
+
+.progress-bar {
+  height: 4px;
+  background: #e2e8f0;
+  border-radius: 2px;
+  margin-top: 4px;
+}
+
+.progress-fill {
+  height: 100%;
+  border-radius: 2px;
+  transition: width 0.3s ease;
+}
+
+/* Edit form */
+.td-status {
+  width: 20px;
+  text-align: center;
+}
+
+.status-active  { color: #27ae60; font-size: 12px; }
+.status-inactive { color: #bdc3c7; font-size: 12px; }
+
+.btn-icon {
+  background: none;
+  border: none;
+  cursor: pointer;
+  font-size: 16px;
+  padding: 2px 4px;
+  margin-right: 2px;
+  border-radius: 3px;
+  line-height: 1;
+  position: relative;
+}
+
+.btn-icon:hover {
+  background: rgba(0, 0, 0, 0.06);
+}
+
+.btn-icon-edit   { color: #2980b9; }
+.btn-icon-warn   { color: #e67e22; }
+.btn-icon-ok     { color: #27ae60; }
+.btn-icon-danger { color: #e74c3c; }
+
+.btn-icon::after {
+  content: attr(data-tooltip);
+  position: absolute;
+  bottom: calc(100% + 8px);
+  left: 50%;
+  transform: translateX(-50%);
+  background: #2c3e50;
+  color: white;
+  padding: 5px 10px;
+  border-radius: 5px;
+  font-size: 12px;
+  font-weight: 400;
+  white-space: nowrap;
+  opacity: 0;
+  pointer-events: none;
+  transition: opacity 0.15s;
+  z-index: 1000;
+}
+
+.btn-icon::before {
+  content: '';
+  position: absolute;
+  bottom: calc(100% + 2px);
+  left: 50%;
+  transform: translateX(-50%);
+  border: 5px solid transparent;
+  border-top-color: #2c3e50;
+  opacity: 0;
+  pointer-events: none;
+  transition: opacity 0.15s;
+  z-index: 1000;
+}
+
+.btn-icon:hover::after,
+.btn-icon:hover::before {
+  opacity: 1;
+}
+
+.action-cell {
+  white-space: nowrap;
+  position: relative;
+  overflow: visible;
+}
+
+.row-editing {
+  background: #eaf4fb !important;
+}
+
+.edit-section {
+  margin-top: 20px;
+  padding: 16px 20px;
+  background: #f0f7ff;
+  border: 1px solid #3498db;
+  border-radius: 6px;
+}
+
+.edit-section h3 {
+  margin: 0 0 14px;
+  font-size: 15px;
+  color: #2c3e50;
+  font-weight: 600;
+}
+
+.edit-section h3 em {
+  font-style: normal;
+  color: #2980b9;
+}
+
+.edit-form {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 14px;
+  align-items: flex-end;
+}
+
+.edit-form label {
+  display: flex;
+  flex-direction: column;
+  gap: 3px;
+  font-size: 13px;
+  font-weight: 500;
+  color: #34495e;
+}
+
+.edit-form label small {
+  font-weight: 400;
+  color: #999;
+  font-size: 11px;
+}
+
+.edit-form input {
+  padding: 6px 8px;
+  border: 1px solid #bdc3c7;
+  border-radius: 4px;
+  font-size: 14px;
+  width: 130px;
+}
+
+.edit-actions {
+  display: flex;
+  gap: 8px;
+  padding-bottom: 2px;
+}
+
+.btn-save {
+  padding: 6px 18px;
+  background: #27ae60;
+  color: white;
+  border: none;
+  border-radius: 4px;
+  cursor: pointer;
+  font-size: 13px;
+}
+
+.btn-save:hover {
+  background: #219a52;
+}
+
+.btn-cancel {
+  padding: 6px 18px;
+  background: #95a5a6;
+  color: white;
+  border: none;
+  border-radius: 4px;
+  cursor: pointer;
+  font-size: 13px;
+}
+
+.btn-cancel:hover {
+  background: #7f8c8d;
+}