feat(hooks): add rules-injector hook for .cursor/rules and .claude/rules support

Implements adaptive rule injection similar to Claude Code's rule system:
- Searches .cursor/rules and .claude/rules directories recursively
- Supports YAML frontmatter with globs, paths, alwaysApply, description
- Adaptive project root detection (finds markers even outside ctx.directory)
- Symlink duplicate detection via realpath comparison
- Content hash deduplication (SHA-256) to avoid re-injecting same rules
- picomatch-based glob pattern matching for file-specific rules

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

src/hooks/rules-injector/constants.ts

@@ -0,0 +1,23 @@
+import { join } from "node:path";
+import { xdgData } from "xdg-basedir";
+
+export const OPENCODE_STORAGE = join(xdgData ?? "", "opencode", "storage");
+export const RULES_INJECTOR_STORAGE = join(OPENCODE_STORAGE, "rules-injector");
+
+export const PROJECT_MARKERS = [
+  ".git",
+  "pyproject.toml",
+  "package.json",
+  "Cargo.toml",
+  "go.mod",
+  ".venv",
+];
+
+export const PROJECT_RULE_SUBDIRS: [string, string][] = [
+  [".cursor", "rules"],
+  [".claude", "rules"],
+];
+
+export const USER_RULE_DIR = ".claude/rules";
+
+export const RULE_EXTENSIONS = [".md", ".mdc"];