webui: Improve dx

For local development, switch to Vite and update web components for improved demo experience. Note that we haven't changed how we bundle when we're actually running in sketch; that's still the go/esbuild in-memory setup. This just changes demo dev setup to get breakpoints working and a functioning full sketch-app-shell.

We still need to add some mock data, but this is a start

- Introduced `vite.config.mts` for Vite setup with hot module reloading.
- Updated `package.json` and `package-lock.json` to include Vite and related plugins.
- Refactored demo scripts to utilize Vite for local development.
- Created `launch.json` for VSCode debugging configuration.
- Enhanced `Makefile` with a new demo task.
- Improved styling and structure in demo HTML and CSS files.
- Implemented `aggregateAgentMessages` function for message handling in web components.
diff --git a/loop/webui/package-lock.json b/loop/webui/package-lock.json
index e4b2748..8abb565 100644
--- a/loop/webui/package-lock.json
+++ b/loop/webui/package-lock.json
@@ -20,18 +20,18 @@
         "vega-lite": "^5.23.0"
       },
       "devDependencies": {
-        "@open-wc/dev-server-hmr": "^0.1.2-next.0",
         "@sand4rt/experimental-ct-web": "^1.51.1",
         "@types/marked": "^5.0.2",
         "@types/mocha": "^10.0.7",
         "@types/node": "^22.13.14",
-        "@web/dev-server": "^0.4.6",
         "@web/test-runner": "^0.18.2",
         "@web/test-runner-puppeteer": "^0.18.0",
         "autoprefixer": "^10.4.21",
         "esbuild": "^0.25.1",
         "prettier": "3.5.3",
-        "typescript": "^5.8.2"
+        "typescript": "^5.8.2",
+        "vite": "^6.3.2",
+        "vite-plugin-web-components-hmr": "^0.1.3"
       }
     },
     "node_modules/@ampproject/remapping": {
@@ -888,99 +888,6 @@
         "node": ">= 8"
       }
     },
-    "node_modules/@open-wc/dev-server-hmr": {
-      "version": "0.1.2-next.0",
-      "resolved": "https://registry.npmjs.org/@open-wc/dev-server-hmr/-/dev-server-hmr-0.1.2-next.0.tgz",
-      "integrity": "sha512-XgazcRuYE0J17X1LgZ/BumwMf81p7qR1h3ncc3ljA3PDqXIBSOYnt1SSoR/IqlJvDmbTopONYQ/w+qjEOtBrAg==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "@babel/core": "^7.12.3",
-        "@babel/plugin-syntax-class-properties": "^7.12.13",
-        "@babel/plugin-syntax-import-assertions": "^7.12.1",
-        "@babel/plugin-syntax-top-level-await": "^7.12.1",
-        "@web/dev-server-core": "^0.3.10",
-        "@web/dev-server-hmr": "^0.1.6",
-        "picomatch": "^2.2.2"
-      }
-    },
-    "node_modules/@open-wc/dev-server-hmr/node_modules/@web/dev-server-core": {
-      "version": "0.3.19",
-      "resolved": "https://registry.npmjs.org/@web/dev-server-core/-/dev-server-core-0.3.19.tgz",
-      "integrity": "sha512-Q/Xt4RMVebLWvALofz1C0KvP8qHbzU1EmdIA2Y1WMPJwiFJFhPxdr75p9YxK32P2t0hGs6aqqS5zE0HW9wYzYA==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "@types/koa": "^2.11.6",
-        "@types/ws": "^7.4.0",
-        "@web/parse5-utils": "^1.2.0",
-        "chokidar": "^3.4.3",
-        "clone": "^2.1.2",
-        "es-module-lexer": "^1.0.0",
-        "get-stream": "^6.0.0",
-        "is-stream": "^2.0.0",
-        "isbinaryfile": "^4.0.6",
-        "koa": "^2.13.0",
-        "koa-etag": "^4.0.0",
-        "koa-send": "^5.0.1",
-        "koa-static": "^5.0.0",
-        "lru-cache": "^6.0.0",
-        "mime-types": "^2.1.27",
-        "parse5": "^6.0.1",
-        "picomatch": "^2.2.2",
-        "ws": "^7.4.2"
-      },
-      "engines": {
-        "node": ">=10.0.0"
-      }
-    },
-    "node_modules/@open-wc/dev-server-hmr/node_modules/@web/parse5-utils": {
-      "version": "1.3.1",
-      "resolved": "https://registry.npmjs.org/@web/parse5-utils/-/parse5-utils-1.3.1.tgz",
-      "integrity": "sha512-haCgDchZrAOB9EhBJ5XqiIjBMsS/exsM5Ru7sCSyNkXVEJWskyyKuKMFk66BonnIGMPpDtqDrTUfYEis5Zi3XA==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "@types/parse5": "^6.0.1",
-        "parse5": "^6.0.1"
-      },
-      "engines": {
-        "node": ">=10.0.0"
-      }
-    },
-    "node_modules/@open-wc/dev-server-hmr/node_modules/isbinaryfile": {
-      "version": "4.0.10",
-      "resolved": "https://registry.npmjs.org/isbinaryfile/-/isbinaryfile-4.0.10.tgz",
-      "integrity": "sha512-iHrqe5shvBUcFbmZq9zOQHBoeOhZJu6RQGrDpBgenUm/Am+F3JM2MgQj+rK3Z601fzrL5gLZWtAPH2OBaSVcyw==",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": ">= 8.0.0"
-      },
-      "funding": {
-        "url": "https://github.com/sponsors/gjtorikian/"
-      }
-    },
-    "node_modules/@open-wc/dev-server-hmr/node_modules/lru-cache": {
-      "version": "6.0.0",
-      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-6.0.0.tgz",
-      "integrity": "sha512-Jo6dJ04CmSjuznwJSS3pUeWmd/H0ffTlkXXgwZi+eq1UCmqQwCh+eLsYOYCwY991i2Fah4h1BEMCx4qThGbsiA==",
-      "dev": true,
-      "license": "ISC",
-      "dependencies": {
-        "yallist": "^4.0.0"
-      },
-      "engines": {
-        "node": ">=10"
-      }
-    },
-    "node_modules/@open-wc/dev-server-hmr/node_modules/yallist": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/yallist/-/yallist-4.0.0.tgz",
-      "integrity": "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A==",
-      "dev": true,
-      "license": "ISC"
-    },
     "node_modules/@playwright/experimental-ct-core": {
       "version": "1.51.1",
       "resolved": "https://registry.npmjs.org/@playwright/experimental-ct-core/-/experimental-ct-core-1.51.1.tgz",
@@ -1756,83 +1663,6 @@
         "url": "https://paulmillr.com/funding/"
       }
     },
-    "node_modules/@web/dev-server-hmr": {
-      "version": "0.1.12",
-      "resolved": "https://registry.npmjs.org/@web/dev-server-hmr/-/dev-server-hmr-0.1.12.tgz",
-      "integrity": "sha512-oqEYVFAh9D74GUigQqxPN5izhocc+A02tZ7Y4QCIHLe6qttjD5R+Hpj8CAObySslfH1X/IGSsWhB8TGctCxlPA==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "@web/dev-server-core": "^0.4.1"
-      },
-      "engines": {
-        "node": ">=10.0.0"
-      }
-    },
-    "node_modules/@web/dev-server-hmr/node_modules/@web/dev-server-core": {
-      "version": "0.4.1",
-      "resolved": "https://registry.npmjs.org/@web/dev-server-core/-/dev-server-core-0.4.1.tgz",
-      "integrity": "sha512-KdYwejXZwIZvb6tYMCqU7yBiEOPfKLQ3V9ezqqEz8DA9V9R3oQWaowckvCpFB9IxxPfS/P8/59OkdzGKQjcIUw==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "@types/koa": "^2.11.6",
-        "@types/ws": "^7.4.0",
-        "@web/parse5-utils": "^1.3.1",
-        "chokidar": "^3.4.3",
-        "clone": "^2.1.2",
-        "es-module-lexer": "^1.0.0",
-        "get-stream": "^6.0.0",
-        "is-stream": "^2.0.0",
-        "isbinaryfile": "^5.0.0",
-        "koa": "^2.13.0",
-        "koa-etag": "^4.0.0",
-        "koa-send": "^5.0.1",
-        "koa-static": "^5.0.0",
-        "lru-cache": "^6.0.0",
-        "mime-types": "^2.1.27",
-        "parse5": "^6.0.1",
-        "picomatch": "^2.2.2",
-        "ws": "^7.4.2"
-      },
-      "engines": {
-        "node": ">=10.0.0"
-      }
-    },
-    "node_modules/@web/dev-server-hmr/node_modules/@web/parse5-utils": {
-      "version": "1.3.1",
-      "resolved": "https://registry.npmjs.org/@web/parse5-utils/-/parse5-utils-1.3.1.tgz",
-      "integrity": "sha512-haCgDchZrAOB9EhBJ5XqiIjBMsS/exsM5Ru7sCSyNkXVEJWskyyKuKMFk66BonnIGMPpDtqDrTUfYEis5Zi3XA==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "@types/parse5": "^6.0.1",
-        "parse5": "^6.0.1"
-      },
-      "engines": {
-        "node": ">=10.0.0"
-      }
-    },
-    "node_modules/@web/dev-server-hmr/node_modules/lru-cache": {
-      "version": "6.0.0",
-      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-6.0.0.tgz",
-      "integrity": "sha512-Jo6dJ04CmSjuznwJSS3pUeWmd/H0ffTlkXXgwZi+eq1UCmqQwCh+eLsYOYCwY991i2Fah4h1BEMCx4qThGbsiA==",
-      "dev": true,
-      "license": "ISC",
-      "dependencies": {
-        "yallist": "^4.0.0"
-      },
-      "engines": {
-        "node": ">=10"
-      }
-    },
-    "node_modules/@web/dev-server-hmr/node_modules/yallist": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/yallist/-/yallist-4.0.0.tgz",
-      "integrity": "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A==",
-      "dev": true,
-      "license": "ISC"
-    },
     "node_modules/@web/dev-server-rollup": {
       "version": "0.6.4",
       "resolved": "https://registry.npmjs.org/@web/dev-server-rollup/-/dev-server-rollup-0.6.4.tgz",
@@ -2271,20 +2101,6 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
-    "node_modules/anymatch": {
-      "version": "3.1.3",
-      "resolved": "https://registry.npmjs.org/anymatch/-/anymatch-3.1.3.tgz",
-      "integrity": "sha512-KMReFUr0B4t+D+OBkjR3KYqvocp2XaSzO55UcB6mgQMd3KbcE+mWTyvVV7D/zsdEbNnV6acZUutkiHQXvTr1Rw==",
-      "dev": true,
-      "license": "ISC",
-      "dependencies": {
-        "normalize-path": "^3.0.0",
-        "picomatch": "^2.0.4"
-      },
-      "engines": {
-        "node": ">= 8"
-      }
-    },
     "node_modules/argparse": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/argparse/-/argparse-2.0.1.tgz",
@@ -2491,19 +2307,6 @@
         "node": ">=10.0.0"
       }
     },
-    "node_modules/binary-extensions": {
-      "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/binary-extensions/-/binary-extensions-2.3.0.tgz",
-      "integrity": "sha512-Ceh+7ox5qe7LJuLHoY0feh3pHuUDHAcRUeyL2VYghZwfpkNIy/+8Ocg0a3UuSoYzavmylwuLWQOf3hl0jjMMIw==",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": ">=8"
-      },
-      "funding": {
-        "url": "https://github.com/sponsors/sindresorhus"
-      }
-    },
     "node_modules/braces": {
       "version": "3.0.3",
       "resolved": "https://registry.npmjs.org/braces/-/braces-3.0.3.tgz",
@@ -2723,31 +2526,6 @@
         "url": "https://github.com/chalk/ansi-styles?sponsor=1"
       }
     },
-    "node_modules/chokidar": {
-      "version": "3.6.0",
-      "resolved": "https://registry.npmjs.org/chokidar/-/chokidar-3.6.0.tgz",
-      "integrity": "sha512-7VT13fmjotKpGipCW9JEQAusEPE+Ei8nl6/g4FBAmIm0GOOLMua9NDDo/DWp0ZAxCr3cPq5ZpBqmPAQgDda2Pw==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "anymatch": "~3.1.2",
-        "braces": "~3.0.2",
-        "glob-parent": "~5.1.2",
-        "is-binary-path": "~2.1.0",
-        "is-glob": "~4.0.1",
-        "normalize-path": "~3.0.0",
-        "readdirp": "~3.6.0"
-      },
-      "engines": {
-        "node": ">= 8.10.0"
-      },
-      "funding": {
-        "url": "https://paulmillr.com/funding/"
-      },
-      "optionalDependencies": {
-        "fsevents": "~2.3.2"
-      }
-    },
     "node_modules/chrome-launcher": {
       "version": "0.15.2",
       "resolved": "https://registry.npmjs.org/chrome-launcher/-/chrome-launcher-0.15.2.tgz",
@@ -4432,19 +4210,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/is-binary-path": {
-      "version": "2.1.0",
-      "resolved": "https://registry.npmjs.org/is-binary-path/-/is-binary-path-2.1.0.tgz",
-      "integrity": "sha512-ZMERYes6pDydyuGidse7OsHxtbI7WVeUEozgR/g7rd0xUimYNlvZRE/K2MgZTjWy725IfelLeVcEM97mmtRGXw==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "binary-extensions": "^2.0.0"
-      },
-      "engines": {
-        "node": ">=8"
-      }
-    },
     "node_modules/is-core-module": {
       "version": "2.16.1",
       "resolved": "https://registry.npmjs.org/is-core-module/-/is-core-module-2.16.1.tgz",
@@ -5218,16 +4983,6 @@
         "node": "*"
       }
     },
-    "node_modules/normalize-path": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-3.0.0.tgz",
-      "integrity": "sha512-6eZs5Ls3WtCisHWp9S2GUy8dqkpGi4BVSz3GaqiE6ezub0512ESztXUwUB6C6IKbQkY2Pnb/mD4WYojCRwcwLA==",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": ">=0.10.0"
-      }
-    },
     "node_modules/normalize-range": {
       "version": "0.1.2",
       "resolved": "https://registry.npmjs.org/normalize-range/-/normalize-range-0.1.2.tgz",
@@ -5915,19 +5670,6 @@
         "node": ">= 0.8"
       }
     },
-    "node_modules/readdirp": {
-      "version": "3.6.0",
-      "resolved": "https://registry.npmjs.org/readdirp/-/readdirp-3.6.0.tgz",
-      "integrity": "sha512-hOS089on8RduqdbhvQ5Z37A0ESjsqz6qnRcffsMU3495FuTdqSm+7bhJ29JvIOsBDEEnan5DPu9t3To9VRlMzA==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "picomatch": "^2.2.1"
-      },
-      "engines": {
-        "node": ">=8.10.0"
-      }
-    },
     "node_modules/require-directory": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/require-directory/-/require-directory-2.1.1.tgz",
@@ -7225,7 +6967,6 @@
       "resolved": "https://registry.npmjs.org/vite/-/vite-6.3.2.tgz",
       "integrity": "sha512-ZSvGOXKGceizRQIZSz7TGJ0pS3QLlVY/9hwxVh17W3re67je1RKYzFHivZ/t0tubU78Vkyb9WnHPENSBCzbckg==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
         "esbuild": "^0.25.0",
         "fdir": "^6.4.3",
@@ -7295,6 +7036,22 @@
         }
       }
     },
+    "node_modules/vite-plugin-web-components-hmr": {
+      "version": "0.1.3",
+      "resolved": "https://registry.npmjs.org/vite-plugin-web-components-hmr/-/vite-plugin-web-components-hmr-0.1.3.tgz",
+      "integrity": "sha512-UF+YYOFyaie6cT7XPatRz2Xo1Fh3TdTwOdCq1Z0EjzMfdAlUiUdF3crkN0DdEhctWBvq18CHxJZUTKw7x1zSRQ==",
+      "dev": true,
+      "dependencies": {
+        "@babel/core": "^7.12.3",
+        "@babel/plugin-syntax-class-properties": "^7.12.13",
+        "@babel/plugin-syntax-import-assertions": "^7.12.1",
+        "@babel/plugin-syntax-top-level-await": "^7.12.1",
+        "picomatch": "^2.2.2"
+      },
+      "peerDependencies": {
+        "vite": ">=2"
+      }
+    },
     "node_modules/vite/node_modules/fdir": {
       "version": "6.4.4",
       "resolved": "https://registry.npmjs.org/fdir/-/fdir-6.4.4.tgz",