fix(rules-core): isolate package + block symlink escape from rule sources

- Drop the back-import of src/shared/logger so @oh-my-opencode/rules-core
  stays free of host-adapter dependencies (ROADMAP package layering
  invariant). Expose setSisyphusRuleDeprecationLogger(logger) for hosts to
  inject their own logger; default is a noop.
- Wire the host injection in src/hooks/rules-injector/rule-file-finder.ts
  as a module-level side effect so existing behavior is preserved.
- Add realpath boundary check to findRuleFilesRecursive and
  validFileRealPath. Project rule scanners now refuse entries whose
  realpath escapes the rule-source root, closing the symlink-escape
  vector where a malicious repo could point .github/copilot-instructions.md
  (or any .omo/rules/* entry) at ~/.ssh/id_rsa and have the rule injector
  pull the secret into model context.

src/hooks/rules-injector/rule-file-finder.ts

@@ -1,2 +1,7 @@
+import { setSisyphusRuleDeprecationLogger } from "@oh-my-opencode/rules-core";
+import { log } from "../../shared/logger";
+
+setSisyphusRuleDeprecationLogger(log);
+
 export { findRuleFiles } from "@oh-my-opencode/rules-core";
 export type { FindRuleFilesOptions } from "@oh-my-opencode/rules-core";