feat: add @claudemesh/sdk package for non-Claude-Code clients

Standalone TypeScript SDK that any process can use to join a mesh and
send/receive messages. Implements the same WS protocol and libsodium
crypto_box encryption as the CLI, with an EventEmitter-based API.

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

packages/connector-slack/src/config.ts

@@ -0,0 +1,71 @@
+/**
+ * Configuration types for the Slack connector.
+ *
+ * All values are loaded from environment variables in index.ts.
+ */
+
+export interface SlackConnectorConfig {
+  // Slack
+  /** Bot User OAuth Token (xoxb-...) */
+  slackBotToken: string;
+  /** App-Level Token for Socket Mode (xapp-...) */
+  slackAppToken: string;
+  /** Channel ID to bridge (e.g. C0123456789) */
+  slackChannelId: string;
+
+  // Mesh
+  /** WebSocket URL of the claudemesh broker (wss://...) */
+  brokerUrl: string;
+  /** Mesh UUID */
+  meshId: string;
+  /** Member UUID (this connector's membership) */
+  memberId: string;
+  /** Ed25519 public key, hex-encoded (64 chars) */
+  pubkey: string;
+  /** Ed25519 secret key, hex-encoded (128 chars) */
+  secretKey: string;
+  /** Display name visible to mesh peers (e.g. "Slack-#general") */
+  displayName: string;
+}
+
+/**
+ * Load config from environment variables, throwing on any missing required var.
+ */
+export function loadConfigFromEnv(): SlackConnectorConfig {
+  const required: Array<[keyof SlackConnectorConfig, string]> = [
+    ["slackBotToken", "SLACK_BOT_TOKEN"],
+    ["slackAppToken", "SLACK_APP_TOKEN"],
+    ["slackChannelId", "SLACK_CHANNEL_ID"],
+    ["brokerUrl", "MESH_BROKER_URL"],
+    ["meshId", "MESH_ID"],
+    ["memberId", "MESH_MEMBER_ID"],
+    ["pubkey", "MESH_PUBKEY"],
+    ["secretKey", "MESH_SECRET_KEY"],
+  ];
+
+  const missing: string[] = [];
+  const values: Record<string, string> = {};
+
+  for (const [key, envVar] of required) {
+    const val = process.env[envVar];
+    if (!val) {
+      missing.push(envVar);
+    } else {
+      values[key] = val;
+    }
+  }
+
+  if (missing.length > 0) {
+    throw new Error(
+      `Missing required environment variables: ${missing.join(", ")}`,
+    );
+  }
+
+  return {
+    ...(values as unknown as Omit<SlackConnectorConfig, "displayName">),
+    displayName:
+      process.env.MESH_DISPLAY_NAME ??
+      process.env.DISPLAY_NAME ??
+      "Slack-connector",
+  };
+}