fix: warn on provider mismatch & fix redundant mobile close button

[ccqqlo]

This PR solves two issues:

1. Auth mismatch warnings (401 errors)
   Selecting an OpenRouter model while Hermes is configured for a local provider (or vice-versa) sends the request to the wrong endpoint, which returns a 401 error. This explicitly detects 401/auth errors, preserving the auth_mismatch UI type and surfacing a hint to check hermes model rather than failing silently.

2. Redundant Workspace Panel close buttons
   When the screen width is <= 900px, both the desktop #btnCollapseWorkspacePanel and the .mobile-close-btn (X) were shown simultaneously in the Workspace header. This explicitly hides the desktop collapse button under mobile widths so only the X is rendered.

[nesquena-hermes]

Check the diff/files changed, is this PR doing what you expect it to be doing?

[nesquena]

Full Review: PR #333

Thanks @ccqqlo!

Note: PR title is misleading

The title says "warn on provider mismatch" but that feature was already merged in PR #283. This PR actually contains:

1. Auto-title expansion (streaming.py) — triggers auto-title on 'New Chat' and empty titles in addition to 'Untitled'
2. Mobile close button CSS fix (style.css) — adds .mobile-close-btn{display:none} default and shows it at 900px breakpoint; hides desktop collapse button on mobile

Both changes are correct and useful, just mislabeled.

Security Audit

Clean. The streaming.py change is a string comparison condition — no user input involved. The CSS change is layout-only.

Code Review

streaming.py line 338:

if s.title == 'Untitled' or s.title == 'New Chat' or not s.title:

Correct. 'New Chat' is used as a default title in some session creation paths. not s.title handles None and empty string. The or chain is clear and readable. Low risk — only affects auto-titling, never overwrites user-set titles.

style.css mobile close button:

• .mobile-close-btn{display:none} at desktop — correct, the button element exists in HTML but should only show on mobile
• .mobile-close-btn{display:flex} at @media(max-width:900px) — correct
• #btnCollapseWorkspacePanel{display:none} at 900px — correct, desktop-only control hidden on mobile

The 900px media query reformatting (one-line → multi-line) is a readability improvement.

Tests

735 passed, 0 failed, 48 skipped. No regressions.

Verdict

Approved. Both changes are correct and low-risk. The PR title should be updated to something like "fix: auto-title new/empty sessions + show mobile close button" but that's cosmetic.

[nesquena-hermes]

Review complete — merged as v0.50.10 ✅

Code review: Clean. Both changes are minimal and correct.

streaming.py — The expanded title condition ('Untitled' or 'New Chat' or not s.title) is a straightforward widening of the existing guard. 'New Chat' is defensive (not a title used internally), and the not s.title guard covers empty-string edge cases. No risk of accidentally re-titling user-renamed sessions — the comment "preserves user renames" holds because the condition only applies to default-state titles.

style.css — .mobile-close-btn{display:none;} at the desktop scope plus the 900px media query overrides are the correct approach. The existing .rightpanel and .mobile-files-btn rules inside that query were preserved. No regressions.

PR description note: The description mentions "auth mismatch warnings" — that code was already in master from PR #283. The actual new code in this PR is the title fix + CSS. Not a problem, just context.

Tests added (not in original PR): tests/test_sprint41.py — 11 tests covering both fixes. All 11 pass on this branch, 6 correctly fail on master before the fix.

QA results:

• 800/802 tests pass (2 pre-existing failures, both on master before this PR)
• Full browser API sanity: 20/20 checks pass
• pre-release-check.sh: ALL CHECKS PASSED

Rebased cleanly onto current master (which had moved to v0.50.9 + zh locale fixes since the PR was filed).

Merged as PR #339 → tag v0.50.10 → release.

[nesquena]

@ccqqlo Interested in being a core contributor to this WebUI project? Reach out to me via email (on my profile) or on Twitter if so!