Replace ansiToHtml with terminal serialization (Phase 2)

The output handler now:
- Writes raw data to terminal emulator
- Stores raw data in DB (unchanged)
- Serializes terminal state as HTML
- Broadcasts serialized HTML via SSE

This replaces the ansiToHtml() + splitAnsiCarryover() approach with
proper terminal emulation. The terminal emulator handles all ANSI
sequences internally, including incomplete sequences across chunks.

src/server.ts

@@ -1,8 +1,6 @@
 // Core server: HTTP + WebSocket + SSE
 
 import type { ServerWebSocket } from "bun";
-import { ansiToHtml } from "./ansi";
-import { splitAnsiCarryover } from "./ansi-carryover";
 import {
   appendOutput,
   createDevice,
@@ -19,7 +17,12 @@ import {
   updateLastSeen,
   updateSessionStats,
 } from "./db";
-import { createTerminal, disposeTerminal, type TerminalSession } from "./terminal";
+import {
+  createTerminal,
+  disposeTerminal,
+  serializeAsHTML,
+  type TerminalSession,
+} from "./terminal";
 import type {
   AnswerResponse,
   ClientMessage,
@@ -494,35 +497,29 @@ const server = Bun.serve<SessionData>({
         // Handle output message
         if (msg.type === "output") {
           const sessionId = ws.data.sessionId;
-          // Join with any saved carryover from previous chunk
-          const prevCarry = ansiCarryovers.get(sessionId) || "";
-          const combined = prevCarry ? prevCarry + msg.data : msg.data;
-          // Determine if new tail is an incomplete control sequence and split
-          const [body, carry] = splitAnsiCarryover(combined);
-          if (carry) {
-            console.debug(
-              `Session ${sessionId}: ANSI carryover detected (${carry.length} bytes)`,
-            );
-            ansiCarryovers.set(sessionId, carry);
-          } else if (prevCarry) {
-            console.debug(`Session ${sessionId}: ANSI carryover resolved`);
-            // Clear carry if previously set and now resolved
-            ansiCarryovers.delete(sessionId);
-          }
-
-          appendOutput(sessionId, body); // Store raw ANSI without trailing incomplete fragment
-
-          // Write to terminal emulator
           const termSession = sessionTerminals.get(sessionId);
-          if (termSession) {
-            termSession.terminal.write(msg.data);
+
+          if (!termSession) {
+            console.error(`No terminal for session ${sessionId}`);
+            return;
           }
 
+          // Write to terminal emulator (handles all ANSI sequences)
+          termSession.terminal.write(msg.data);
+
+          // Store raw ANSI in database
+          appendOutput(sessionId, msg.data);
+
+          // Serialize current terminal state as HTML
+          const html = serializeAsHTML(termSession);
+
+          // Broadcast to dashboards
           broadcastSSE({
             type: "output",
             session_id: sessionId,
-            data: ansiToHtml(body), // Parse for display
+            data: html,
           });
+
           return;
         }