refactor: switch to basedpyright, remove pydantic-settings

- Replace pyright with basedpyright in devenv.nix (custom hook)
- Add basedpyright to devenv packages
- Fix all basedpyright warnings: add DiGraph[str] type args, annotate
  class attributes, narrow SyncResponse, handle unused call results,
  suppress unavoidable Any from yaml.safe_load and untyped blackforest
- Replace pydantic-settings[yaml] with direct pyyaml dependency
- Update CLAUDE.md to reflect basedpyright and dependency changes

bulkgen/graph.py

@@ -9,7 +9,7 @@ import networkx as nx
 from bulkgen.config import ProjectConfig
 
 
-def build_graph(config: ProjectConfig, project_dir: Path) -> nx.DiGraph:
+def build_graph(config: ProjectConfig, project_dir: Path) -> nx.DiGraph[str]:
     """Build a dependency DAG from the project configuration.
 
     Nodes are filenames: target names (keys in ``config.targets``) and
@@ -19,7 +19,7 @@ def build_graph(config: ProjectConfig, project_dir: Path) -> nx.DiGraph:
     Raises :class:`ValueError` if a dependency is neither a defined target
     nor an existing file, or if the graph contains a cycle.
     """
-    graph = nx.DiGraph()
+    graph: nx.DiGraph[str] = nx.DiGraph()
     target_names = set(config.targets)
 
     for target_name, target_cfg in config.targets.items():
@@ -37,7 +37,7 @@ def build_graph(config: ProjectConfig, project_dir: Path) -> nx.DiGraph:
                     f"which is neither a defined target nor an existing file"
                 )
                 raise ValueError(msg)
-            graph.add_edge(dep, target_name)
+            _ = graph.add_edge(dep, target_name)
 
     if not nx.is_directed_acyclic_graph(graph):
         cycles = list(nx.simple_cycles(graph))
@@ -47,7 +47,7 @@ def build_graph(config: ProjectConfig, project_dir: Path) -> nx.DiGraph:
     return graph
 
 
-def get_build_order(graph: nx.DiGraph) -> list[list[str]]:
+def get_build_order(graph: nx.DiGraph[str]) -> list[list[str]]:
     """Return targets grouped into generations for parallel execution.
 
     Each inner list contains nodes with no inter-dependencies that can
@@ -56,9 +56,9 @@ def get_build_order(graph: nx.DiGraph) -> list[list[str]]:
     return [list(gen) for gen in nx.topological_generations(graph)]
 
 
-def get_subgraph_for_target(graph: nx.DiGraph, target: str) -> nx.DiGraph:
+def get_subgraph_for_target(graph: nx.DiGraph[str], target: str) -> nx.DiGraph[str]:
     """Return the subgraph containing *target* and all its transitive dependencies."""
-    ancestors = nx.ancestors(graph, target)
+    ancestors: set[str] = nx.ancestors(graph, target)  # pyright: ignore[reportUnknownMemberType]
     ancestors.add(target)
-    subgraph = nx.DiGraph(graph.subgraph(ancestors))
+    subgraph: nx.DiGraph[str] = nx.DiGraph(graph.subgraph(ancestors))
     return subgraph