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-cli/src/commands/init.rs

@@ -49,6 +49,14 @@ pub fn init_project(root: &str, out: &str) -> Result<()> {
 
 ---
 
+## Integrations
+<!-- ARCHDOC:BEGIN section=integrations -->
+> Generated. Do not edit inside this block.
+<AUTO: detected integrations by category>
+<!-- ARCHDOC:END section=integrations -->
+
+---
+
 ## Rails / Tooling
 <!-- ARCHDOC:BEGIN section=rails -->
 > Generated. Do not edit inside this block.

archdoc-cli/src/output.rs

@@ -24,6 +24,8 @@ pub fn print_generate_summary(model: &ProjectModel) {
         if model.symbols.values().any(|s| s.integrations_flags.http) { v.push("HTTP"); }
         if model.symbols.values().any(|s| s.integrations_flags.db) { v.push("DB"); }
         if model.symbols.values().any(|s| s.integrations_flags.queue) { v.push("Queue"); }
+        if model.symbols.values().any(|s| s.integrations_flags.storage) { v.push("Storage"); }
+        if model.symbols.values().any(|s| s.integrations_flags.ai) { v.push("AI/ML"); }
         v
     };
     if !integrations.is_empty() {