feat(quick-260327-x64): implement listSkills/syncSkills on Claude, Codex, and Gemini adapters

- Add skills.ts to Claude adapter: ephemeral mode, listClaudeSkills/syncClaudeSkills
- Add skills.ts to Codex adapter: ephemeral mode, listCodexSkills/syncCodexSkills
- Add skills.ts to Gemini adapter: persistent mode with symlink sync, listGeminiSkills/syncGeminiSkills
- Re-export skill functions from each adapter's server/index.ts

packages/adapter-gemini-local/src/server/index.ts

@@ -7,6 +7,7 @@ export {
   detectGeminiAuthRequired,
   isGeminiTurnLimitResult,
 } from "./parse.js";
+export { listGeminiSkills, syncGeminiSkills } from "./skills.js";
 import type { AdapterSessionCodec } from "@agentcompany/adapter-utils";
 
 function readNonEmptyString(value: unknown): string | null {

packages/adapter-gemini-local/src/server/skills.ts

@@ -0,0 +1,113 @@
+// ---------------------------------------------------------------------------
+// Gemini adapter skill listing / sync -- persistent mode
+// Skills are symlinked into ~/.gemini/skills/ and persist across runs.
+// ---------------------------------------------------------------------------
+
+import { promises as fs } from "node:fs";
+import path from "node:path";
+import type {
+  AdapterSkillContext,
+  AdapterSkillSnapshot,
+} from "@agentcompany/adapter-utils";
+import {
+  parseObject,
+  asString,
+  readAgentCompanyRuntimeSkillEntries,
+  readInstalledSkillTargets,
+  resolveAgentCompanyDesiredSkillNames,
+  buildPersistentSkillSnapshot,
+  ensureAgentCompanySkillSymlink,
+  removeMaintainerOnlySkillSymlinks,
+} from "@agentcompany/adapter-utils/server-utils";
+
+function resolveGeminiSkillsHome(config: Record<string, unknown>): string {
+  const env = parseObject(config.env);
+  const home = asString(env.HOME, asString(env.USERPROFILE, ""));
+  const base = home || (process.env.HOME ?? process.env.USERPROFILE ?? "");
+  return path.join(base, ".gemini", "skills");
+}
+
+async function buildGeminiSkillSnapshot(
+  config: Record<string, unknown>,
+): Promise<AdapterSkillSnapshot> {
+  const moduleDir = path.resolve(import.meta.dirname ?? __dirname);
+  const availableEntries = await readAgentCompanyRuntimeSkillEntries(config, moduleDir);
+  const desiredSkills = resolveAgentCompanyDesiredSkillNames(config, availableEntries);
+  const skillsHome = resolveGeminiSkillsHome(config);
+  const installed = await readInstalledSkillTargets(skillsHome);
+
+  return buildPersistentSkillSnapshot({
+    adapterType: "gemini_local",
+    availableEntries,
+    desiredSkills,
+    installed,
+    skillsHome,
+    locationLabel: "~/.gemini/skills",
+    missingDetail: "Configured but not currently linked into the Gemini skills home.",
+    externalConflictDetail: "Skill name is occupied by an external installation.",
+    externalDetail: "Installed outside AgentCompany management.",
+  });
+}
+
+/**
+ * List the current skill state for the Gemini adapter.
+ * Persistent mode: reports actual installed state in ~/.gemini/skills/.
+ */
+export async function listGeminiSkills(
+  ctx: AdapterSkillContext,
+): Promise<AdapterSkillSnapshot> {
+  return buildGeminiSkillSnapshot(ctx.config);
+}
+
+/**
+ * Sync skills for the Gemini adapter.
+ * Persistent mode: creates symlinks for desired skills, removes stale ones,
+ * then returns a fresh snapshot.
+ */
+export async function syncGeminiSkills(
+  ctx: AdapterSkillContext,
+  desiredSkills: string[],
+): Promise<AdapterSkillSnapshot> {
+  const moduleDir = path.resolve(import.meta.dirname ?? __dirname);
+  const config = ctx.config;
+  const availableEntries = await readAgentCompanyRuntimeSkillEntries(config, moduleDir);
+  const skillsHome = resolveGeminiSkillsHome(config);
+
+  // Ensure the skills home directory exists
+  await fs.mkdir(skillsHome, { recursive: true });
+
+  // Build a set of desired skill keys for quick lookup
+  const desiredSet = new Set(desiredSkills);
+
+  // Symlink type for Windows compatibility
+  const symlinkType = process.platform === "win32" ? ("junction" as const) : undefined;
+  const linkSkill = async (source: string, target: string) => {
+    await fs.symlink(source, target, symlinkType);
+  };
+
+  // Create/repair symlinks for desired skills
+  const syncedRuntimeNames = new Set<string>();
+  for (const available of availableEntries) {
+    if (!desiredSet.has(available.key)) continue;
+    const target = path.join(skillsHome, available.runtimeName);
+    await ensureAgentCompanySkillSymlink(available.source, target, linkSkill);
+    syncedRuntimeNames.add(available.runtimeName);
+  }
+
+  // Remove stale maintainer-only symlinks that are no longer desired
+  await removeMaintainerOnlySkillSymlinks(skillsHome, syncedRuntimeNames);
+
+  // Return fresh snapshot reflecting the new state
+  const installed = await readInstalledSkillTargets(skillsHome);
+  return buildPersistentSkillSnapshot({
+    adapterType: "gemini_local",
+    availableEntries,
+    desiredSkills,
+    installed,
+    skillsHome,
+    locationLabel: "~/.gemini/skills",
+    missingDetail: "Configured but not currently linked into the Gemini skills home.",
+    externalConflictDetail: "Skill name is occupied by an external installation.",
+    externalDetail: "Installed outside AgentCompany management.",
+  });
+}