feat(09-01): extract GitHub fetch helpers to shared module

- Create github-skill-helpers.ts with fetchText, fetchJson, resolveGitHubDefaultBranch, resolveGitHubCommitSha, parseGitHubSourceUrl, resolveGitHubPinnedRef, resolveRawGitHubUrl
- Update company-skills.ts to import from github-skill-helpers.js instead of defining locally
- All existing company-skill tests pass (15/15)

server/src/services/company-skills.ts

@@ -30,6 +30,15 @@ import { normalizeAgentUrlKey } from "@paperclipai/shared";
 import { findServerAdapter } from "../adapters/index.js";
 import { resolvePaperclipInstanceRoot } from "../home-paths.js";
 import { notFound, unprocessable } from "../errors.js";
+import {
+  fetchText,
+  fetchJson,
+  resolveGitHubDefaultBranch,
+  resolveGitHubCommitSha,
+  parseGitHubSourceUrl,
+  resolveGitHubPinnedRef,
+  resolveRawGitHubUrl,
+} from "./github-skill-helpers.js";
 import { agentService } from "./agents.js";
 import { projectService } from "./projects.js";
 import { secretService } from "./secrets.js";
@@ -469,90 +478,8 @@ function parseFrontmatterMarkdown(raw: string): { frontmatter: Record<string, un
   };
 }
 
-async function fetchText(url: string) {
+// [nexus] GitHub helpers extracted to shared module — imported below
-  const response = await fetch(url);
-  if (!response.ok) {
-    throw unprocessable(`Failed to fetch ${url}: ${response.status}`);
-  }
-  return response.text();
-}
 
-async function fetchJson<T>(url: string): Promise<T> {
-  const response = await fetch(url, {
-    headers: {
-      accept: "application/vnd.github+json",
-    },
-  });
-  if (!response.ok) {
-    throw unprocessable(`Failed to fetch ${url}: ${response.status}`);
-  }
-  return response.json() as Promise<T>;
-}
-
-async function resolveGitHubDefaultBranch(owner: string, repo: string) {
-  const response = await fetchJson<{ default_branch?: string }>(
-    `https://api.github.com/repos/${owner}/${repo}`,
-  );
-  return asString(response.default_branch) ?? "main";
-}
-
-async function resolveGitHubCommitSha(owner: string, repo: string, ref: string) {
-  const response = await fetchJson<{ sha?: string }>(
-    `https://api.github.com/repos/${owner}/${repo}/commits/${encodeURIComponent(ref)}`,
-  );
-  const sha = asString(response.sha);
-  if (!sha) {
-    throw unprocessable(`Failed to resolve GitHub ref ${ref}`);
-  }
-  return sha;
-}
-
-function parseGitHubSourceUrl(rawUrl: string) {
-  const url = new URL(rawUrl);
-  if (url.hostname !== "github.com") {
-    throw unprocessable("GitHub source must use github.com URL");
-  }
-  const parts = url.pathname.split("/").filter(Boolean);
-  if (parts.length < 2) {
-    throw unprocessable("Invalid GitHub URL");
-  }
-  const owner = parts[0]!;
-  const repo = parts[1]!.replace(/\.git$/i, "");
-  let ref = "main";
-  let basePath = "";
-  let filePath: string | null = null;
-  let explicitRef = false;
-  if (parts[2] === "tree") {
-    ref = parts[3] ?? "main";
-    basePath = parts.slice(4).join("/");
-    explicitRef = true;
-  } else if (parts[2] === "blob") {
-    ref = parts[3] ?? "main";
-    filePath = parts.slice(4).join("/");
-    basePath = filePath ? path.posix.dirname(filePath) : "";
-    explicitRef = true;
-  }
-  return { owner, repo, ref, basePath, filePath, explicitRef };
-}
-
-async function resolveGitHubPinnedRef(parsed: ReturnType<typeof parseGitHubSourceUrl>) {
-  if (/^[0-9a-f]{40}$/i.test(parsed.ref.trim())) {
-    return {
-      pinnedRef: parsed.ref,
-      trackingRef: parsed.explicitRef ? parsed.ref : null,
-    };
-  }
-
-  const trackingRef = parsed.explicitRef
-    ? parsed.ref
-    : await resolveGitHubDefaultBranch(parsed.owner, parsed.repo);
-  const pinnedRef = await resolveGitHubCommitSha(parsed.owner, parsed.repo, trackingRef);
-  return { pinnedRef, trackingRef };
-}
-
-function resolveRawGitHubUrl(owner: string, repo: string, ref: string, filePath: string) {
-  return `https://raw.githubusercontent.com/${owner}/${repo}/${ref}/${filePath.replace(/^\/+/, "")}`;
-}
 
 function extractCommandTokens(raw: string) {
   const matches = raw.match(/"[^"]*"|'[^']*'|\S+/g) ?? [];

server/src/services/github-skill-helpers.ts

@@ -0,0 +1,102 @@
+import path from "node:path";
+import { unprocessable } from "../errors.js";
+
+function asString(value: unknown): string | undefined {
+  if (typeof value !== "string") return undefined;
+  const trimmed = value.trim();
+  return trimmed.length > 0 ? trimmed : undefined;
+}
+
+export async function fetchText(url: string): Promise<string> {
+  const response = await fetch(url);
+  if (!response.ok) {
+    throw unprocessable(`Failed to fetch ${url}: ${response.status}`);
+  }
+  return response.text();
+}
+
+export async function fetchJson<T>(url: string): Promise<T> {
+  const response = await fetch(url, {
+    headers: {
+      accept: "application/vnd.github+json",
+    },
+  });
+  if (!response.ok) {
+    throw unprocessable(`Failed to fetch ${url}: ${response.status}`);
+  }
+  return response.json() as Promise<T>;
+}
+
+export async function resolveGitHubDefaultBranch(owner: string, repo: string): Promise<string> {
+  const response = await fetchJson<{ default_branch?: string }>(
+    `https://api.github.com/repos/${owner}/${repo}`,
+  );
+  return asString(response.default_branch) ?? "main";
+}
+
+export async function resolveGitHubCommitSha(owner: string, repo: string, ref: string): Promise<string> {
+  const response = await fetchJson<{ sha?: string }>(
+    `https://api.github.com/repos/${owner}/${repo}/commits/${encodeURIComponent(ref)}`,
+  );
+  const sha = asString(response.sha);
+  if (!sha) {
+    throw unprocessable(`Failed to resolve GitHub ref ${ref}`);
+  }
+  return sha;
+}
+
+export function parseGitHubSourceUrl(rawUrl: string): {
+  owner: string;
+  repo: string;
+  ref: string;
+  basePath: string;
+  filePath: string | null;
+  explicitRef: boolean;
+} {
+  const url = new URL(rawUrl);
+  if (url.hostname !== "github.com") {
+    throw unprocessable("GitHub source must use github.com URL");
+  }
+  const parts = url.pathname.split("/").filter(Boolean);
+  if (parts.length < 2) {
+    throw unprocessable("Invalid GitHub URL");
+  }
+  const owner = parts[0]!;
+  const repo = parts[1]!.replace(/\.git$/i, "");
+  let ref = "main";
+  let basePath = "";
+  let filePath: string | null = null;
+  let explicitRef = false;
+  if (parts[2] === "tree") {
+    ref = parts[3] ?? "main";
+    basePath = parts.slice(4).join("/");
+    explicitRef = true;
+  } else if (parts[2] === "blob") {
+    ref = parts[3] ?? "main";
+    filePath = parts.slice(4).join("/");
+    basePath = filePath ? path.posix.dirname(filePath) : "";
+    explicitRef = true;
+  }
+  return { owner, repo, ref, basePath, filePath, explicitRef };
+}
+
+export async function resolveGitHubPinnedRef(
+  parsed: ReturnType<typeof parseGitHubSourceUrl>,
+): Promise<{ pinnedRef: string; trackingRef: string | null }> {
+  if (/^[0-9a-f]{40}$/i.test(parsed.ref.trim())) {
+    return {
+      pinnedRef: parsed.ref,
+      trackingRef: parsed.explicitRef ? parsed.ref : null,
+    };
+  }
+
+  const trackingRef = parsed.explicitRef
+    ? parsed.ref
+    : await resolveGitHubDefaultBranch(parsed.owner, parsed.repo);
+  const pinnedRef = await resolveGitHubCommitSha(parsed.owner, parsed.repo, trackingRef);
+  return { pinnedRef, trackingRef };
+}
+
+export function resolveRawGitHubUrl(owner: string, repo: string, ref: string, filePath: string): string {
+  return `https://raw.githubusercontent.com/${owner}/${repo}/${ref}/${filePath.replace(/^\/+/, "")}`;
+}