feat(omo-codex): add post-compact rule budget to codex hook

Trim rule and result char budgets after compaction via new
postCompactMaxRuleChars/postCompactMaxResultChars config, applied
through withPostCompactBudget. Extract codex-hook helpers into
dynamic-target-fingerprints, hook-output, path-utils,
rules-engine-factory, and transcript-rule-filter modules.

packages/omo-codex/plugin/components/rules/src/path-utils.ts

@@ -0,0 +1,29 @@
+import { isAbsolute, relative, resolve } from "node:path";
+
+export function displayPath(cwd: string, filePath: string): string {
+	const rel = isAbsolute(filePath) ? relative(cwd, filePath) : filePath;
+	return toPosixPath(rel);
+}
+
+export function isSameOrChildPath(childPath: string, parentPath: string): boolean {
+	const childRelativePath = relative(parentPath, resolve(childPath));
+	return childRelativePath === "" || (!childRelativePath.startsWith("..") && !isAbsolute(childRelativePath));
+}
+
+export function toPosixPath(path: string): string {
+	return path.replaceAll("\\", "/");
+}
+
+export function uniqueStrings(values: ReadonlyArray<string>): string[] {
+	const uniqueValues: string[] = [];
+	const seenValues = new Set<string>();
+	for (const value of values) {
+		if (seenValues.has(value)) {
+			continue;
+		}
+
+		seenValues.add(value);
+		uniqueValues.push(value);
+	}
+	return uniqueValues;
+}