feat: serve schemas based on which tags exist on gh

conf.py

@@ -102,20 +102,55 @@ def build_served_html():
     from pathlib import Path
 
     os.chdir(Path(__file__).parent)
-    versions = [
+
+    # Create .htaccess to serve schemas inline (not download)
+    os.makedirs("_html_extra", exist_ok=True)
+    htaccess_content = """<FilesMatch "\\.schema$">
+    Header set Content-Disposition "inline"
+</FilesMatch>
+"""
+    with open("_html_extra/.htaccess", "w") as f:
+        f.write(htaccess_content)
+    print(f"✅ Created .htaccess to serve schemas inline")
+
+    # Fetch GitHub tags and download schemas
+    try:
+        result = subprocess.check_output([
+            "git", "ls-remote", "--tags", "https://github.com/ome/ngff-spec"
+        ], text=True, timeout=10)
+        tags = [line.split()[1].replace("refs/tags/", "").rstrip("^{}") for line in result.strip().split("\n") if line]
+        for tag in sorted(set(tags)):
+            schema_dir = f"_html_extra/{tag}/schemas"
+            os.makedirs(schema_dir, exist_ok=True)
+            # Download schemas from GitHub raw for this tag
+            gh_url = f"https://github.com/ome/ngff-spec/archive/refs/tags/{tag}.tar.gz"
+            try:
+                import tempfile, tarfile
+                with tempfile.NamedTemporaryFile(delete=False) as tmp:
+                    subprocess.check_call(["curl", "-sL", gh_url, "-o", tmp.name])
+                    with tarfile.open(tmp.name) as tar:
+                        for member in tar.getmembers():
+                            if "/schemas/" in member.name and member.name.endswith(".schema"):
+                                # Extract just the filename, flatten into schema_dir
+                                target = os.path.join(schema_dir, os.path.basename(member.name))
+                                tar.extract(member, path=tempfile.gettempdir())
+                                src = os.path.join(tempfile.gettempdir(), member.name)
+                                shutil.copy2(src, target)
+                    os.unlink(tmp.name)
+                print(f"✅ Downloaded schemas for {tag}")
+            except Exception as e:
+                print(f"⚠️  Could not download schemas for {tag}: {e}")
+    except Exception:
+        pass
+
+    # Build specifications from local submodules
+    displayed_spec_versions = [
         d
         for d in os.listdir("specifications")
         if os.path.isdir(os.path.join("specifications", d))
     ]
 
-    for version in versions:
-
-        # copy schemas to _html_extra
-        os.makedirs(f"_html_extra/{version}/schemas", exist_ok=True)
-        schemas = glob.glob(f"specifications/{version}/**/*.schema", recursive=True)
-        for schema in schemas:
-            shutil.copy2(schema, f"_html_extra/{version}/schemas/")
-        print(f"✅ Copied schemas for version {version}")
+    for version in displayed_spec_versions:
 
         # find 'pre_build.py' in 'specifications' subdirectories
         script = glob.glob(f"specifications/{version}/**/pre_build.py", recursive=True)[