a plugin declares its chat directory; email stops being hardcoded here

ChatPanelWrapper had one plugin's screen id compiled into a shared platform
package: `workspace.id === 'email'` → `{ context: 'email' }`. its own comment
said the general fix was a way for a plugin to DECLARE its chat context, and
that a second hardcoded id would be the signal it was needed. that fix exists
(`declared`), the email plugin now passes it, so the branch is gone.

it also could not fire any more, which is the part worth keeping. a plugin's
workspace key is `screens/plugin/<name>`, so email's id became `plugin/email`
the day it was extracted and the test silently stopped matching. a hardcoded id
does not fail loudly when the thing it names moves — it just stops being true,
and nothing said so for eight days.

two things on the backend half:

resolveEmailCwd now installs the email plugin's chat/CLAUDE.md. an email chat
runs in the account's directory, not the plugin's chats directory, so the
`plugin` branch never reaches it — the brief follows the chat rather than the
chat moving to the brief. a second plugin wanting this is the signal that
"which directory does this chat run in" belongs in the manifest.

and it verifies the mailbox exists before joining it. `accountEmail` comes from
the client (the mailbox picker's `?account=`) and this function ends in mkdirSync
— so an unrecognised value did not fail, it CREATED a directory named after
whatever arrived and ran the turn in it. the list's unified view uses the
sentinel `all`, which is the value most likely to show up by accident. the panel
drops it; this is the half that does not depend on the panel remembering to.

docs/claude-md-touchpoints.md updated: the copier now has two callers.

unrelated and NOT from this change: ModelSelector's "an unstarted composer gets
a default" fails on master too — verified by stashing these files and rerunning.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Officer-Session: 656f5c85-e49a-4f1f-b9f3-042a04b4d043

src/workspaces/officerdev/src/apps/Chat/ChatPanelWrapper.tsx

@@ -203,24 +203,21 @@ export const ChatPanelWrapper = ({
   // `contextId` stays the raw workspace key: it is the same string `agent_panels.dashboard_id` holds, and
   // a stored address should not be two different strings depending on which feature wrote it. The bare id
   // is for deciding, which is what `kind` and `id` are doing above it.
-  // `'email'` is a PLUGIN's screen id, hardcoded in a shared platform package, and it is the one piece of
-  // plugin vocabulary the extraction on 2026-08-18 could not remove.
   //
-  // It is the frontend half of a pair: this sends `context: 'email'`, and the chat socket answers it by
-  // running the turn in that mailbox's directory (`resolveEmailCwd`). The backend half carries its own
-  // justification; this line is recorded here so the coupling is visible from both ends rather than only
-  // one. If the email plugin is not installed, no workspace has this id and the branch is simply never
-  // taken — it fails to nothing rather than to an error.
+  // There WAS a third branch here — `workspace.id === 'email'` → `{ context: 'email' }` — one plugin's
+  // screen id hardcoded in a shared platform package. Its own comment said the general fix was a way for a
+  // plugin to DECLARE its chat context, and that a second hardcoded id would be the signal it was needed.
+  // `declared` is that fix, and the email plugin now passes it, so the branch is gone.
   //
-  // The general fix is a way for a plugin to declare a chat context, which does not exist. Until it does,
-  // adding a SECOND id here is the signal that it needs to.
+  // It also could not fire any more, which is the part worth keeping: a plugin's workspace key is
+  // `screens/plugin/<name>`, so email's id became `plugin/email` the day it was extracted and the test
+  // silently stopped matching. Every email chat since ran with no mailbox anywhere near it. A hardcoded id
+  // does not fail loudly when the thing it names moves — it just stops being true.
   const chatContext = declared
     ? declared
-    : workspace?.kind === 'screen' && workspace.id === 'email'
-      ? { context: 'email' as const }
-      : workspace?.kind === 'dashboard'
-        ? { context: 'dashboard' as const, contextId: workspace.key }
-        : {};
+    : workspace?.kind === 'dashboard'
+      ? { context: 'dashboard' as const, contextId: workspace.key }
+      : {};
 
   const agentPanel = useAgentPanel(panelId);