Add CLI package, config file support, and workspace setup

Add cli/ package with initial scaffolding. Add config-schema to shared
package for typed configuration. Add server config-file loader for
paperclip.config.ts support. Register cli in pnpm workspace. Add
.paperclip/ and .pnpm-store/ to gitignore. Minor Companies page fix.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

cli/src/checks/llm-check.ts

@@ -0,0 +1,86 @@
+import type { PaperclipConfig } from "../config/schema.js";
+import type { CheckResult } from "./index.js";
+
+export async function llmCheck(config: PaperclipConfig): Promise<CheckResult> {
+  if (!config.llm) {
+    return {
+      name: "LLM provider",
+      status: "warn",
+      message: "No LLM provider configured",
+      canRepair: false,
+      repairHint: "Run `paperclip configure --section llm` to set one up",
+    };
+  }
+
+  if (!config.llm.apiKey) {
+    return {
+      name: "LLM provider",
+      status: "warn",
+      message: `${config.llm.provider} configured but no API key set`,
+      canRepair: false,
+      repairHint: "Run `paperclip configure --section llm`",
+    };
+  }
+
+  try {
+    if (config.llm.provider === "claude") {
+      const res = await fetch("https://api.anthropic.com/v1/messages", {
+        method: "POST",
+        headers: {
+          "x-api-key": config.llm.apiKey,
+          "anthropic-version": "2023-06-01",
+          "content-type": "application/json",
+        },
+        body: JSON.stringify({
+          model: "claude-sonnet-4-5-20250929",
+          max_tokens: 1,
+          messages: [{ role: "user", content: "hi" }],
+        }),
+      });
+      if (res.ok || res.status === 400) {
+        return { name: "LLM provider", status: "pass", message: "Claude API key is valid" };
+      }
+      if (res.status === 401) {
+        return {
+          name: "LLM provider",
+          status: "fail",
+          message: "Claude API key is invalid (401)",
+          canRepair: false,
+          repairHint: "Run `paperclip configure --section llm`",
+        };
+      }
+      return {
+        name: "LLM provider",
+        status: "warn",
+        message: `Claude API returned status ${res.status}`,
+      };
+    } else {
+      const res = await fetch("https://api.openai.com/v1/models", {
+        headers: { Authorization: `Bearer ${config.llm.apiKey}` },
+      });
+      if (res.ok) {
+        return { name: "LLM provider", status: "pass", message: "OpenAI API key is valid" };
+      }
+      if (res.status === 401) {
+        return {
+          name: "LLM provider",
+          status: "fail",
+          message: "OpenAI API key is invalid (401)",
+          canRepair: false,
+          repairHint: "Run `paperclip configure --section llm`",
+        };
+      }
+      return {
+        name: "LLM provider",
+        status: "warn",
+        message: `OpenAI API returned status ${res.status}`,
+      };
+    }
+  } catch {
+    return {
+      name: "LLM provider",
+      status: "warn",
+      message: "Could not reach API to validate key",
+    };
+  }
+}