#1126 Use the chat organization for Claude Web

Summary

Claude.ai (Web) fails with s.map is not a function for accounts linked to the Anthropic Console. /api/organizations lists the API-only organization first (capabilities ["api", "customer_terms:standard"]), and Claude.init() always took organizations[0]. claude.ai answers chat_conversations for that organization with a permission_error object instead of a list:

 Claude.init()
   getOrganizations()
-  organizationId = organizations[0].uuid
+  organizationId = first organization whose capabilities include "chat"
+                   ?? organizations[0]
   getConversations()
-    json.map(...)   // json = { type: "error", error: { type: "permission_error" } } → TypeError
+    if json is not an array → throw Error(json.error.message)
+    json.map(...)

The client's fetch-sse import also gets its .mjs extension so the module loads under the Node test runner. Webpack resolves both forms the same way.

Evidence

• Before: the new tests run against the old init():

  ✖ Claude init prefers the organization with chat capability
    Error: unexpected request /api/organizations/api-org/chat_conversations
  ✖ Claude init reports the claude.ai error when conversations are denied
    actual: TypeError: json.map is not a function
  

  In the extension, every Claude.ai (Web) question ends with the error s.map is not a function.

  After:

  ✔ Claude init prefers the organization with chat capability
  ✔ Claude init falls back to the first organization without chat capability
  ✔ Claude init reports the claude.ai error when conversations are denied
  

  Claude.ai (Web) answers normally again in Firefox for the affected account.

Validation: npm test (1110 pass), npm run lint, npm run pretty:check and npm run build are clean. Manually tested in Firefox with an affected account, using a build that also carried #996; the Claude client code is identical to this PR. Not manually tested in Chromium.

Merge Danger

Door: two-way

Blast Radius: Claude Web only

Accounts with a single organization, or whose first organization already has chat, keep the organization they used before. If claude.ai stops reporting chat in capabilities, the client falls back to the old organizations[0] behavior.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Claude now selects an organization with chat access when available, helping ensure chat features work with the appropriate account.
  • Conversation-loading failures now show the error message provided by the service, or a fallback message when none is available.