chore: polish for FOL contract delivery (CHANGELOG, CLI guardrails, metadata)

- Update CHANGELOG.md for 1.1.0 (date, refactoring, repository fixes)
- Add overwrite guardrails to imhotep-cli init — skips existing files
- Add bugs/homepage/keywords metadata to 5 public packages
- Mark imhotep-bench and imhotep-fixtures as private packages
- Add selector field to SourceReference interface (core types)
- Remove 7  casts from check-all.ts (folAst.position, cardinality results)
- Generate package-lock.json for reproducible installs

packages/imhotep-core/src/types.ts

@@ -251,6 +251,8 @@ export interface SourceReference {
   specLine?: number
   /** 1-based column number in the dense spec string */
   specColumn?: number
+  /** CSS or semantic selector for cardinality assertions */
+  selector?: string
 }
 
 export interface ClauseResult {