feat(node): add TypeScript sibling project for npm-based install

Introduces @kuns/claude-mailbox under node/, a wire-compatible TypeScript
port of the .NET daemon that distributes via the public Gitea npm registry.
The .NET project stays in src/ClaudeMailbox/ untouched; users pick whichever
flavor they prefer.

- node/ project: fastify + @modelcontextprotocol/sdk StreamableHTTPServerTransport
  + better-sqlite3, schema and wire surface match the C# version (port 47822,
  X-Mailbox header, MCP tool names, snake_case SQLite columns)
- Cross-platform autostart: Scheduled Task (Win, no admin) / Windows Service
  (Win, --service) / launchd (mac) / systemd --user (linux)
- 9/9 vitest tests pass; end-to-end /health + send/check round-trip verified
- CI split: existing ci.yml/release.yml renamed to *-dotnet.yml with path
  filters, new ci-node.yml and release-node.yml publish to Gitea npm registry
- install.ps1 / install.sh bootstrap one-liners at repo root; homebrew/
  contains a tap formula template
- README install section reordered: npm path primary, dotnet publish secondary

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitea/workflows/release-node.yml

@@ -0,0 +1,116 @@
+name: Release (Node)
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    env:
+      GITEA_API: https://git.kuns.dev/api/v1
+      REPO: releases/ClaudeMailbox
+      NPM_REGISTRY_HOST: git.kuns.dev/api/packages/releases/npm/
+    defaults:
+      run:
+        working-directory: node
+    steps:
+      - name: Checkout tag
+        uses: https://github.com/actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Node version
+        run: node --version && npm --version
+
+      - name: Resolve version
+        id: ver
+        run: |
+          set -euo pipefail
+          TAG="${{ github.ref_name }}"
+          VERSION="${TAG#v}"
+          echo "tag=$TAG"         >> "$GITHUB_OUTPUT"
+          echo "version=$VERSION" >> "$GITHUB_OUTPUT"
+
+      - name: Set package version
+        env:
+          VERSION: ${{ steps.ver.outputs.version }}
+        run: npm version --no-git-tag-version "$VERSION"
+
+      - name: Install
+        run: npm ci
+
+      - name: Test
+        run: npm test
+
+      - name: Build
+        run: npm run build
+
+      - name: Pack
+        env:
+          VERSION: ${{ steps.ver.outputs.version }}
+        run: |
+          set -euo pipefail
+          npm pack
+          mv "kuns-claude-mailbox-${VERSION}.tgz" "claude-mailbox-${VERSION}.tgz"
+          ( sha256sum "claude-mailbox-${VERSION}.tgz" > checksums.txt )
+
+      - name: Configure npm auth for Gitea
+        env:
+          NPM_TOKEN: ${{ secrets.GITEA_TOKEN }}
+        run: |
+          set -euo pipefail
+          echo "@kuns:registry=https://${NPM_REGISTRY_HOST}" > .npmrc
+          echo "//${NPM_REGISTRY_HOST}:_authToken=${NPM_TOKEN}" >> .npmrc
+
+      - name: Publish to Gitea npm registry
+        run: npm publish --access public
+
+      - name: Find or create Gitea release
+        id: release
+        env:
+          TAG:   ${{ steps.ver.outputs.tag }}
+          TOKEN: ${{ secrets.GITEA_TOKEN }}
+        run: |
+          set -euo pipefail
+          # Try to find an existing release for this tag (the .NET workflow may have created it).
+          EXISTING=$(curl -sS \
+            -H "Authorization: token ${TOKEN}" \
+            "${GITEA_API}/repos/${REPO}/releases/tags/${TAG}" || echo "")
+          RELEASE_ID=$(echo "$EXISTING" | jq -r '.id // empty')
+          if [ -z "$RELEASE_ID" ] || [ "$RELEASE_ID" = "null" ]; then
+            BODY=$(jq -n \
+              --arg tag  "$TAG" \
+              --arg name "$TAG" \
+              '{tag_name:$tag, name:$name, body:"", draft:false, prerelease:false, target_commitish:"main"}')
+            RESP=$(curl -sS -X POST \
+              -H "Authorization: token ${TOKEN}" \
+              -H "Content-Type: application/json" \
+              -d "$BODY" \
+              "${GITEA_API}/repos/${REPO}/releases")
+            RELEASE_ID=$(echo "$RESP" | jq -r '.id // empty')
+          fi
+          if [ -z "$RELEASE_ID" ] || [ "$RELEASE_ID" = "null" ]; then
+            echo "::error::Could not resolve release id" >&2
+            exit 1
+          fi
+          echo "release_id=$RELEASE_ID" >> "$GITHUB_OUTPUT"
+
+      - name: Upload tarball + checksums
+        env:
+          VERSION:    ${{ steps.ver.outputs.version }}
+          RELEASE_ID: ${{ steps.release.outputs.release_id }}
+          TOKEN:      ${{ secrets.GITEA_TOKEN }}
+        run: |
+          set -euo pipefail
+          for f in \
+            "claude-mailbox-${VERSION}.tgz" \
+            "checksums.txt"
+          do
+            curl -sS --fail-with-body -X POST \
+              -H "Authorization: token ${TOKEN}" \
+              -F "attachment=@${f}" \
+              "${GITEA_API}/repos/${REPO}/releases/${RELEASE_ID}/assets?name=${f}" \
+              > /dev/null
+          done