feat: add BuildCodeGraph use case, sink orchestration out of presentation

crates/application/src/use_cases/build_code_graph.rs

@@ -0,0 +1,67 @@
+use std::path::Path;
+
+use archlens_domain::{
+    AnalysisConfig, AnalysisWarning, DiagramLevel, DomainError, NormalizedGraph,
+    ports::{FileDiscovery, ProjectAnalyzer, SourceAnalyzer},
+};
+
+use crate::queries::AnalyzeCodebase;
+
+#[derive(Debug)]
+pub struct BuildCodeGraphResult {
+    pub graph: NormalizedGraph,
+    pub warnings: Vec<AnalysisWarning>,
+}
+
+pub struct BuildCodeGraph<F, S>
+where
+    F: FileDiscovery + Send + Sync,
+    S: SourceAnalyzer,
+{
+    pub discovery: F,
+    pub source_analyzer: S,
+    pub project_analyzer: Option<Box<dyn ProjectAnalyzer>>,
+}
+
+impl<F, S> BuildCodeGraph<F, S>
+where
+    F: FileDiscovery + Send + Sync,
+    S: SourceAnalyzer,
+{
+    pub fn execute(
+        self,
+        root: &Path,
+        config: &AnalysisConfig,
+        level: DiagramLevel,
+    ) -> Result<BuildCodeGraphResult, DomainError> {
+        match level {
+            DiagramLevel::Project => {
+                let pa = self.project_analyzer.ok_or_else(|| {
+                    DomainError::AnalysisError(
+                        "no project analyzer available for Project level".into(),
+                    )
+                })?;
+                let cg = pa.analyze(root)?;
+                Ok(BuildCodeGraphResult {
+                    graph: NormalizedGraph::from_project(cg),
+                    warnings: Vec::new(),
+                })
+            }
+            DiagramLevel::Module | DiagramLevel::Type => {
+                let analyze = AnalyzeCodebase::new(self.discovery, self.source_analyzer);
+                let result = analyze.execute(root, config)?;
+                let mut graph = result.graph().clone();
+                if level == DiagramLevel::Module {
+                    if let Some(pa) = self.project_analyzer {
+                        let project_cg = pa.analyze(root)?;
+                        graph.merge_project_edges(&project_cg);
+                    }
+                }
+                Ok(BuildCodeGraphResult {
+                    graph,
+                    warnings: result.warnings().to_vec(),
+                })
+            }
+        }
+    }
+}

crates/application/src/use_cases/mod.rs

@@ -1,3 +1,4 @@
+pub mod build_code_graph;
 pub mod check_freshness;
 pub mod diff_diagram;
 pub mod generate_diagram;