feat(resource): add cloud infrastructure resources

Implement cloud resource types (aws, gcp, azure) with credential
fields, region/tenant metadata, and stubbed sandbox strategies.
Credential resolution uses environment variables and profile names
with no secrets logged.

Key changes:
- Add CloudResourceHandler with aws/gcp/azure type definitions
- Add credential resolution from env vars and profile names
- Add stubbed sandbox strategies (validate config, raise NotImplementedError)
- Register cloud types in bootstrap_builtin_types
- Credential masking via existing redaction patterns
- Add Behave BDD tests, Robot integration tests, ASV benchmarks

ISSUES CLOSED: #343

hooks/adr_hooks.py

@@ -132,7 +132,7 @@ def _build_status_badge(status: str, extra_class: str = "") -> str:
 
 
 def _resolve_adr_link(adr_number: int, files: Any) -> str | None:
-    """Find the relative URL for an ADR by its number, using the MkDocs files collection."""
+    """Find the relative URL for an ADR by its number."""
     prefix = f"adr/ADR-{adr_number:03d}"
     for f in files:
         if f.src_path.startswith(prefix) and f.src_path.endswith(".md"):
@@ -189,7 +189,10 @@ def _build_header(
                 f'<a href="{link}">ADR-{superseded_by:03d}</a>'
             )
         else:
-            superseded_part = f' <span class="adr-label">— superseded by ADR-{superseded_by:03d}</span>'
+            superseded_part = (
+                f' <span class="adr-label">'
+                f"— superseded by ADR-{superseded_by:03d}</span>"
+            )
 
     line2 = (
         f'<div class="adr-header-line">'
@@ -664,12 +667,8 @@ def on_page_markdown(
         generated_h1 = f"# ADR-{int(adr_number):03d}: {adr_title}\n"
     else:
         # Fallback: keep whatever H1 already exists
-        generated_h1 = ""
         h1_match = re.match(r"(#\s+.+?\n)", markdown)
-        if h1_match:
-            generated_h1 = ""  # leave it in the markdown
-        else:
-            generated_h1 = ""
+        generated_h1 = ""  # leave existing H1 or use empty
 
     # ── build header + timeline ─────────────────────────────────────
     header_html = _build_header(