feat(cis): add CCTranscriptionPanel Live tab to sidebar (Phase 1)

- Add CCTranscriptionPanel component with Live tab
- Add Zustand transcriptionStore for session state management
- Wire panel into BasePanel sidebar system
- Fix merged switch cases in getIconForPanel, getDescriptionForPanel, renderCurrentPanel
- Add VITE_WHISPERLIVE_URL to .env

src/stores/transcriptionStore.ts

@@ -0,0 +1,68 @@
+import { create } from 'zustand';
+
+export interface TranscriptionSegment {
+  text: string;
+  isFinal: boolean;
+  start: number;
+  end: number;
+}
+
+interface TranscriptionState {
+  isRecording: boolean;
+  isConnecting: boolean;
+  completedSegments: TranscriptionSegment[];
+  currentSegment: TranscriptionSegment | null;
+  wordCount: number;
+  elapsedSeconds: number;
+
+  startSession: () => void;
+  stopSession: () => void;
+  saveSegment: (text: string, isFinal: boolean, metadata: { start: number; end: number }) => void;
+  resetSession: () => void;
+  tickElapsed: () => void;
+}
+
+export const useTranscriptionStore = create<TranscriptionState>((set, get) => ({
+  isRecording: false,
+  isConnecting: false,
+  completedSegments: [],
+  currentSegment: null,
+  wordCount: 0,
+  elapsedSeconds: 0,
+
+  startSession: () => {
+    set({ isRecording: true, isConnecting: false, elapsedSeconds: 0 });
+  },
+
+  stopSession: () => {
+    set({ isRecording: false, isConnecting: false });
+  },
+
+  saveSegment: (text: string, isFinal: boolean, metadata: { start: number; end: number }) => {
+    const { completedSegments, currentSegment } = get();
+
+    if (isFinal) {
+      // Final segment — move current to completed, clear current
+      const newCompleted = [...completedSegments];
+      if (currentSegment && currentSegment.text.trim()) {
+        newCompleted.push({ ...currentSegment, isFinal: true });
+      }
+      const newWordCount = newCompleted.reduce(
+        (sum, seg) => sum + seg.text.trim().split(/\s+/).filter(Boolean).length,
+        0
+      );
+      set({ completedSegments: newCompleted, currentSegment: null, wordCount: newWordCount });
+    } else {
+      // In-progress segment
+      set({ currentSegment: { text, isFinal: false, ...metadata } });
+    }
+  },
+
+  resetSession: () => {
+    set({ isRecording: false, isConnecting: false, completedSegments: [], currentSegment: null, wordCount: 0, elapsedSeconds: 0 });
+  },
+
+  tickElapsed: () => {
+    set((state) => ({ elapsedSeconds: state.elapsedSeconds + 1 }));
+  },
+}));