feat: integrate Changesets for multi-package npm publishing

Migrate from single-bundle CLI publishing to publishing all @paperclipai/*
packages individually via Changesets. This fixes the "Cannot find package
@paperclipai/server" error when installing from npm.

Changes:
- Add @changesets/cli with fixed versioning (all packages share version)
- Make 7 packages publishable (shared, adapter-utils, db, 3 adapters, server)
- Add build scripts, publishConfig, and files fields to all packages
- Mark @paperclipai/server as external in CLI esbuild config
- Simplify CLI importServerEntry() to use string-literal dynamic import
- Add generate-npm-package-json support for external workspace packages
- Create scripts/release.sh for one-command releases
- Remove old bump-and-publish.sh and version-bump.sh
- All packages start at version 0.2.0

Usage: ./scripts/release.sh patch|minor|major [--dry-run]

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

cli/esbuild.config.mjs

@@ -12,10 +12,10 @@ import { fileURLToPath } from "node:url";
 const __dirname = dirname(fileURLToPath(import.meta.url));
 const repoRoot = resolve(__dirname, "..");
 
-// Workspace packages whose code should be bundled into the CLI
+// Workspace packages whose code should be bundled into the CLI.
+// Note: "server" is excluded — it's published separately and resolved at runtime.
 const workspacePaths = [
   "cli",
-  "server",
   "packages/db",
   "packages/shared",
   "packages/adapter-utils",
@@ -24,17 +24,31 @@ const workspacePaths = [
   "packages/adapters/openclaw",
 ];
 
+// Workspace packages that should NOT be bundled — they'll be published
+// to npm and resolved at runtime (e.g. @paperclipai/server uses dynamic import).
+const externalWorkspacePackages = new Set([
+  "@paperclipai/server",
+]);
+
 // Collect all external (non-workspace) npm package names
 const externals = new Set();
 for (const p of workspacePaths) {
   const pkg = JSON.parse(readFileSync(resolve(repoRoot, p, "package.json"), "utf8"));
   for (const name of Object.keys(pkg.dependencies || {})) {
-    if (!name.startsWith("@paperclipai/")) externals.add(name);
+    if (externalWorkspacePackages.has(name)) {
+      externals.add(name);
+    } else if (!name.startsWith("@paperclipai/")) {
+      externals.add(name);
+    }
   }
   for (const name of Object.keys(pkg.optionalDependencies || {})) {
     externals.add(name);
   }
 }
+// Also add all published workspace packages as external
+for (const name of externalWorkspacePackages) {
+  externals.add(name);
+}
 
 /** @type {import('esbuild').BuildOptions} */
 export default {