feat(electrobun): add xterm.js terminal with image addon (Sixel/iTerm2)

- Terminal.svelte component with @xterm/xterm + Canvas + Fit + Image addons
- Catppuccin Mocha terminal theme matching main app
- Sixel, iTerm2 inline image protocol support via xterm-addon-image
- ResizeObserver for responsive terminal sizing
- Demo cargo test output in terminal section below agent messages

ui-electrobun/bun.lock

@@ -5,6 +5,10 @@
     "": {
       "name": "electrobun-svelte",
       "dependencies": {
+        "@xterm/addon-canvas": "^0.7.0",
+        "@xterm/addon-fit": "^0.11.0",
+        "@xterm/addon-image": "^0.9.0",
+        "@xterm/xterm": "^6.0.0",
         "electrobun": "latest",
       },
       "devDependencies": {
@@ -148,6 +152,14 @@
 
     "@types/node": ["@types/node@25.0.3", "", { "dependencies": { "undici-types": "~7.16.0" } }, "sha512-W609buLVRVmeW693xKfzHeIV6nJGGz98uCPfeXI1ELMLXVeKYZ9m15fAMSaUPBHYLGFsVRcMmSCksQOrZV9BYA=="],
 
+    "@xterm/addon-canvas": ["@xterm/addon-canvas@0.7.0", "", { "peerDependencies": { "@xterm/xterm": "^5.0.0" } }, "sha512-LF5LYcfvefJuJ7QotNRdRSPc9YASAVDeoT5uyXS/nZshZXjYplGXRECBGiznwvhNL2I8bq1Lf5MzRwstsYQ2Iw=="],
+
+    "@xterm/addon-fit": ["@xterm/addon-fit@0.11.0", "", {}, "sha512-jYcgT6xtVYhnhgxh3QgYDnnNMYTcf8ElbxxFzX0IZo+vabQqSPAjC3c1wJrKB5E19VwQei89QCiZZP86DCPF7g=="],
+
+    "@xterm/addon-image": ["@xterm/addon-image@0.9.0", "", {}, "sha512-oYWA8/QAr5/Emwl1xL7WCoOqeG3IZfpzEz/OVq1j4Oi9934TQmHiyubClikRf0D/jL3JNiNuz/Lsqx0kXQ02BA=="],
+
+    "@xterm/xterm": ["@xterm/xterm@6.0.0", "", {}, "sha512-TQwDdQGtwwDt+2cgKDLn0IRaSxYu1tSUjgKarSDkUM0ZNiSRXFpjxEsvc/Zgc5kq5omJ+V0a8/kIM2WD3sMOYg=="],
+
     "acorn": ["acorn@8.15.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-NZyJarBfL7nWwIq+FDL6Zp/yHEhePMNnnJ0y3qfieCrmNvYct8uvtiV41UvlSe6apAfk0fY1FbWx+NwfmpvtTg=="],
 
     "agent-base": ["agent-base@7.1.4", "", {}, "sha512-MnA+YT8fwfJPgBx3m60MNqakm30XOkyIoH1y6huTQvC0PwZG7ki8NacLBcrPbNoo8vEZy7Jpuk7+jMO+CUovTQ=="],