Self-hosted dashboards served over plain HTTP on a LAN have no
navigator.clipboard (insecure context), so every direct writeText call
silently failed. web/src/lib/clipboard.ts already ships the HTTP-safe
copyTextToClipboard fallback but only OAuthLoginModal used it; ChatPage
(OSC 52 + Ctrl/Cmd+Shift+C), ProfilesPage, SystemPage, and WebhooksPage
all bypassed it. Route them through the helper and add a source-level
regression test that rejects any new direct clipboard write outside
lib/clipboard.ts (clipboard reads are exempt: no legacy fallback exists).
Sabotage-verified: the guard test fails when a direct write is introduced.
3ef63373f8