Add Bootstrappers section, essays index, specs prose, layout fixes

- New Bootstrappers top-level section with overview index and JS bootstrapper
  page that runs bootstrap_js.py and displays both source and generated output
  with live script injection (full page load, not SX navigation)
- Essays section: index page with linked cards and summaries, sx-sucks moved
  to end of nav, removed "grand tradition" line
- Specs: English prose descriptions alongside all canonical .sx specs, added
  Boot/CSSX/Browser spec files to architecture page
- Layout: menu bar nav items wrap instead of overflow, baseline alignment
  between label and nav options
- Homepage: added copyright line

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

sx/sxc/pages/helpers.py

@@ -17,6 +17,7 @@ def _register_sx_helpers() -> None:
         "reference-data": _reference_data,
         "attr-detail-data": _attr_detail_data,
         "read-spec-file": _read_spec_file,
+        "bootstrapper-data": _bootstrapper_data,
     })
 
 
@@ -118,6 +119,47 @@ def _read_spec_file(filename: str) -> str:
         return ";; spec file not found"
 
 
+def _bootstrapper_data(target: str) -> dict:
+    """Return bootstrapper source and generated output for a target.
+
+    Returns a dict whose keys become SX env bindings:
+    - bootstrapper-source: the Python bootstrapper source code
+    - bootstrapped-output: the generated JavaScript
+    - bootstrapper-not-found: truthy if target unknown
+    """
+    import os
+
+    if target != "javascript":
+        return {"bootstrapper-not-found": True}
+
+    ref_dir = os.path.join(os.path.dirname(__file__), "..", "..", "shared", "sx", "ref")
+    if not os.path.isdir(ref_dir):
+        ref_dir = "/app/shared/sx/ref"
+
+    # Read bootstrapper source
+    bs_path = os.path.join(ref_dir, "bootstrap_js.py")
+    try:
+        with open(bs_path, encoding="utf-8") as f:
+            bootstrapper_source = f.read()
+    except FileNotFoundError:
+        bootstrapper_source = "# bootstrapper source not found"
+
+    # Run the bootstrap to generate JS
+    from shared.sx.ref.bootstrap_js import compile_ref_to_js
+    try:
+        bootstrapped_output = compile_ref_to_js(
+            adapters=["dom", "engine", "orchestration", "boot", "cssx"]
+        )
+    except Exception as e:
+        bootstrapped_output = f"// bootstrap error: {e}"
+
+    return {
+        "bootstrapper-not-found": None,
+        "bootstrapper-source": bootstrapper_source,
+        "bootstrapped-output": bootstrapped_output,
+    }
+
+
 def _attr_detail_data(slug: str) -> dict:
     """Return attribute detail data for a specific attribute slug.