feat: Enable npx execution directly from GitHub URL

This commit modifies the packaging setup to allow the CLI to be
executed directly from its GitHub URL using `npx`, for example:
`npx https://github.com/google-gemini/gemini-cli` (once merged to main).
This is achieved without requiring the bundle to be checked into
the repository.

Key changes and motivations:

- Modify `scripts.prepare` to run `npm run bundle`:
  Ensures the CLI bundle is generated automatically when `npx`
  installs the package from a git URL. This replaces previous
  approaches (e.g., using `prepack`) which were not consistently
  triggered in the `npx` environment.

- Update `scripts.bundle` to use a direct path for `esbuild`
  and externalize `sqlite3`:
  Using `node_modules/.bin/esbuild` provides a more reliable way
  to invoke the bundler. Externalizing `sqlite3` is crucial for
  correctly handling its native addon, preventing runtime errors.

- Add `bin`, `files`, and root `sqlite3` dependency:
  - The `bin` field defines the `gemini` command.
  - The `files` array ensures the generated `bundle/` directory is
    recognized by npm.
  - `sqlite3` is added as a root dependency to ensure it's
    installed by `npx` when `gemini-code` is fetched, allowing the
    externalized module to be resolved.

These changes collectively ensure that the necessary build artifacts
are created on-the-fly during `npx` installation, providing a
seamless execution experience directly from the GitHub repository URL.

eslint.config.js

@@ -33,6 +33,7 @@ export default tseslint.config(
       'packages/cli/dist/**',
       'packages/server/dist/**',
       'eslint-rules/*',
+      'bundle/**',
     ],
   },
   eslint.configs.recommended,

package-lock.json

@@ -10,6 +10,12 @@
       "workspaces": [
         "packages/*"
       ],
+      "dependencies": {
+        "sqlite3": "^5.1.7"
+      },
+      "bin": {
+        "gemini": "bundle/gemini.js"
+      },
       "devDependencies": {
         "@types/mime-types": "^2.1.4",
         "@vitest/coverage-v8": "^3.1.1",

package.json

@@ -11,6 +11,7 @@
     "build:sandbox": "scripts/build_sandbox.sh",
     "build:all": "npm run build && npm run build:sandbox",
     "clean": "scripts/clean.sh",
+    "prepare": "npm run bundle",
     "test": "npm run test --workspaces",
     "coverage": "npm run coverage --workspaces --if-present",
     "start": "NODE_ENV=development scripts/start.sh",
@@ -24,7 +25,20 @@
     "auth:docker": "gcloud auth configure-docker us-west1-docker.pkg.dev",
     "auth": "npm run auth:npm && npm run auth:docker",
     "prerelease:dev": "npm run prerelease:version --workspaces && npm run prerelease:deps --workspaces",
-    "bundle": "esbuild packages/cli/index.ts --bundle --outfile=bundle/gemini.js --platform=node --format=esm --banner:js=\"import { createRequire } from 'module'; const require = createRequire(import.meta.url); globalThis.__filename = require('url').fileURLToPath(import.meta.url); globalThis.__dirname = require('path').dirname(globalThis.__filename);\" && bash scripts/copy_bundle_assets.sh"
+    "bundle": "node_modules/.bin/esbuild packages/cli/index.ts --bundle --outfile=bundle/gemini.js --platform=node --format=esm --external:sqlite3 --banner:js=\"import { createRequire } from 'module'; const require = createRequire(import.meta.url); globalThis.__filename = require('url').fileURLToPath(import.meta.url); globalThis.__dirname = require('path').dirname(globalThis.__filename);\" && bash scripts/copy_bundle_assets.sh"
+  },
+  "bin": {
+    "gemini": "bundle/gemini.js"
+  },
+  "files": [
+    "bundle/",
+    "packages/cli/dist",
+    "packages/cli/package.json",
+    "packages/server/dist",
+    "packages/server/package.json"
+  ],
+  "dependencies": {
+    "sqlite3": "^5.1.7"
   },
   "devDependencies": {
     "@types/mime-types": "^2.1.4",