feat: security hardening, production roadmap, admin panel v1

Client security fixes (cmd/tailscale-tray/main.go):
- SSRF protection in Add Server dialog (validateControlURL): reject
  private/loopback/link-local/cloud-metadata IPs via DNS resolution
- RCE gate on AuthURL/BrowseToURL exec paths (validateAuthURL)
- Sanitized URL logging (sanitizeURLForLog drops query auth tokens)
- Error handling on exec.Command with user-facing showError()

Admin panel security (web-admin):
- Bcrypt password hashing (replaces SHA256)
- Rate limiting: 5 failed logins → 15-min lockout
- Session + login attempt cleanup goroutine (hourly)
- url.QueryEscape / encodeURIComponent for all API params
- Fail-hard startup when no TLS and non-loopback bind
- ADMIN_PASSWORD required (no default), password min 12 chars
- Username regex whitelist

Installer hardening (Setup.wxs):
- util:PermissionEx restricts SCM access: only Administrators +
  SYSTEM can start/stop/reconfigure service. Authenticated Users
  limited to QueryStatus/QueryConfig/Interrogate
- Vital="yes" on ServiceInstall

Docs & roadmap:
- PRODUCTION_ROADMAP.md: 5-milestone plan (security + features +
  distribution + ops) with granular tasks, effort, done-when
- CLIENT_SECURITY_AUDIT.md, SECURITY_FIXES.md, DEPLOYMENT.md
- AI assistant rules (.cursorrules, .antigravityrules, etc.)

Build & distribution:
- build-msi.ps1, deploy-and-sign.ps1, sign-release.ps1
- redeploy.ps1, tray-deploy.ps1, test-msi.ps1
- installer/msi/ alternative WXS setup
- Restored .github/workflows/ removed in mirror cleanup

.gitignore hardened: *.pfx, *.p12, *.key, *.pem, .env*

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,83 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ main, release-branch/* ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ main ]
+  merge_group:
+    branches: [ main ]
+  schedule:
+    - cron: '31 14 * * 5'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+    # Install a more recent Go that understands modern go.mod content.
+    - name: Install Go
+      uses: actions/setup-go@4b73464bb391d4059bd26b0524d20df3927bd417 # v6.3.0
+      with:
+        go-version-file: go.mod
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@38697555549f1db7851b81482ff19f1fa5c4fedc # v4.34.1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@38697555549f1db7851b81482ff19f1fa5c4fedc # v4.34.1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@38697555549f1db7851b81482ff19f1fa5c4fedc # v4.34.1