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/index.ts

@@ -0,0 +1,150 @@
+import type { PluginInput } from "@opencode-ai/plugin";
+import { readFileSync } from "node:fs";
+import { homedir } from "node:os";
+import { relative, resolve } from "node:path";
+import { findProjectRoot, findRuleFiles } from "./finder";
+import {
+  createContentHash,
+  isDuplicateByContentHash,
+  isDuplicateByRealPath,
+  shouldApplyRule,
+} from "./matcher";
+import { parseRuleFrontmatter } from "./parser";
+import {
+  clearInjectedRules,
+  loadInjectedRules,
+  saveInjectedRules,
+} from "./storage";
+
+interface ToolExecuteInput {
+  tool: string;
+  sessionID: string;
+  callID: string;
+}
+
+interface ToolExecuteOutput {
+  title: string;
+  output: string;
+  metadata: unknown;
+}
+
+interface EventInput {
+  event: {
+    type: string;
+    properties?: unknown;
+  };
+}
+
+interface RuleToInject {
+  relativePath: string;
+  matchReason: string;
+  content: string;
+  distance: number;
+}
+
+const TRACKED_TOOLS = ["read", "write", "edit", "multiedit"];
+
+export function createRulesInjectorHook(ctx: PluginInput) {
+  const sessionCaches = new Map<
+    string,
+    { contentHashes: Set<string>; realPaths: Set<string> }
+  >();
+
+  function getSessionCache(sessionID: string): {
+    contentHashes: Set<string>;
+    realPaths: Set<string>;
+  } {
+    if (!sessionCaches.has(sessionID)) {
+      sessionCaches.set(sessionID, loadInjectedRules(sessionID));
+    }
+    return sessionCaches.get(sessionID)!;
+  }
+
+  function resolveFilePath(title: string): string | null {
+    if (!title) return null;
+    if (title.startsWith("/")) return title;
+    return resolve(ctx.directory, title);
+  }
+
+  const toolExecuteAfter = async (
+    input: ToolExecuteInput,
+    output: ToolExecuteOutput
+  ) => {
+    if (!TRACKED_TOOLS.includes(input.tool.toLowerCase())) return;
+
+    const filePath = resolveFilePath(output.title);
+    if (!filePath) return;
+
+    const projectRoot = findProjectRoot(filePath);
+    const cache = getSessionCache(input.sessionID);
+    const home = homedir();
+
+    const ruleFileCandidates = findRuleFiles(projectRoot, home, filePath);
+    const toInject: RuleToInject[] = [];
+
+    for (const candidate of ruleFileCandidates) {
+      if (isDuplicateByRealPath(candidate.realPath, cache.realPaths)) continue;
+
+      try {
+        const rawContent = readFileSync(candidate.path, "utf-8");
+        const { metadata, body } = parseRuleFrontmatter(rawContent);
+
+        const matchResult = shouldApplyRule(metadata, filePath, projectRoot);
+        if (!matchResult.applies) continue;
+
+        const contentHash = createContentHash(body);
+        if (isDuplicateByContentHash(contentHash, cache.contentHashes)) continue;
+
+        const relativePath = projectRoot
+          ? relative(projectRoot, candidate.path)
+          : candidate.path;
+
+        toInject.push({
+          relativePath,
+          matchReason: matchResult.reason ?? "matched",
+          content: body,
+          distance: candidate.distance,
+        });
+
+        cache.realPaths.add(candidate.realPath);
+        cache.contentHashes.add(contentHash);
+      } catch {}
+    }
+
+    if (toInject.length === 0) return;
+
+    toInject.sort((a, b) => a.distance - b.distance);
+
+    for (const rule of toInject) {
+      output.output += `\n\n[Rule: ${rule.relativePath}]\n[Match: ${rule.matchReason}]\n${rule.content}`;
+    }
+
+    saveInjectedRules(input.sessionID, cache);
+  };
+
+  const eventHandler = async ({ event }: EventInput) => {
+    const props = event.properties as Record<string, unknown> | undefined;
+
+    if (event.type === "session.deleted") {
+      const sessionInfo = props?.info as { id?: string } | undefined;
+      if (sessionInfo?.id) {
+        sessionCaches.delete(sessionInfo.id);
+        clearInjectedRules(sessionInfo.id);
+      }
+    }
+
+    if (event.type === "session.compacted") {
+      const sessionID = (props?.sessionID ??
+        (props?.info as { id?: string } | undefined)?.id) as string | undefined;
+      if (sessionID) {
+        sessionCaches.delete(sessionID);
+        clearInjectedRules(sessionID);
+      }
+    }
+  };
+
+  return {
+    "tool.execute.after": toolExecuteAfter,
+    event: eventHandler,
+  };
+}