Session 2026-10-05: ChatGPT OAuth connection (DCR confidential clients and CIMD) #381

Fixed ChatGPT's 'Only public PKCE clients are supported' (#376), added Client ID Metadata Documents (#378), both deployed and verified live; removed a personal device name from UI texts and git history (#375).

Commits after the history rewrite: 828f824 (DCR accepts none/client_secret_post/client_secret_basic; discovery advertises exactly these) and 1896b19 (CIMD); #375's text change was folded into the whole history by git filter-repo, so it has no commit of its own. A backup bundle from before the rewrite is at D:/Development/Conderis-before-history-rewrite.bundle (still contains the old name; delete when no longer needed). #376/#378 deployed with Publish-Web.ps1 -Deploy; smoke test passed. Live checks: discovery lists none + client_id_metadata_document_supported, authorize with https://chatgpt.com/oauth/client.json redirects to login, DCR with client_secret_post returns 201 (this probe left an unused client named 'probe' in production). #375 is NOT deployed yet (deploy was not permitted in auto mode). Open: user retries the ChatGPT connector dialog; earlier versions of tasks #375/#376 and of this memory still show the old name in item history and need deletion by the owner; #377 untouched.