Add live self-hosting bootstrapper page to bootstrappers section

- Update plan page with completion status and results
- Add ~bootstrapper-self-hosting-content component with live G0/G1 verification
- Add _self_hosting_data() helper: loads py.sx, runs it, diffs against G0
- Add "Self-Hosting (py.sx)" to bootstrappers nav and index table
- Wire /bootstrappers/self-hosting route

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

sx/sxc/pages/docs.sx

@@ -448,13 +448,25 @@
   :data (bootstrapper-data slug)
   :content (if bootstrapper-not-found
     (~spec-not-found :slug slug)
-    (if (= slug "python")
-      (~bootstrapper-py-content
-        :bootstrapper-source bootstrapper-source
-        :bootstrapped-output bootstrapped-output)
-      (~bootstrapper-js-content
-        :bootstrapper-source bootstrapper-source
-        :bootstrapped-output bootstrapped-output))))
+    (case slug
+      "self-hosting"
+        (~bootstrapper-self-hosting-content
+          :py-sx-source py-sx-source
+          :g0-output g0-output
+          :g1-output g1-output
+          :defines-matched defines-matched
+          :defines-total defines-total
+          :g0-lines g0-lines
+          :g0-bytes g0-bytes
+          :verification-status verification-status)
+      "python"
+        (~bootstrapper-py-content
+          :bootstrapper-source bootstrapper-source
+          :bootstrapped-output bootstrapped-output)
+      :else
+        (~bootstrapper-js-content
+          :bootstrapper-source bootstrapper-source
+          :bootstrapped-output bootstrapped-output))))
 
 ;; ---------------------------------------------------------------------------
 ;; Isomorphism section