fix: all 4 archdoc issues — cycles, layout, integrations, usage examples

1. Module Cycles: properly format cycle paths as A → B → C → A
2. Repository layout: group by top-level directory with file counts
3. Integration detection: match patterns against import names (substring),
   add Storage and AI/ML categories to all templates and summary
4. Usage examples: extract __init__ required params for class constructors

Also fix golden test to use ends_with for module-prefixed symbol IDs.

archdoc-core/tests/renderer_tests.rs

@@ -28,6 +28,8 @@ fn test_render_with_integrations() {
             db: true,
             http: false,
             queue: false,
+            storage: false,
+            ai: false,
         },
         metrics: SymbolMetrics {
             fan_in: 0,
@@ -54,6 +56,8 @@ fn test_render_with_integrations() {
             db: false,
             http: true,
             queue: false,
+            storage: false,
+            ai: false,
         },
         metrics: SymbolMetrics {
             fan_in: 0,