fix(tui): support pasting into text inputs

[jp2195]

Problem

Bracketed paste was never handled. The top-level Update matched only KeyPressMsg, so tea.PasteMsg fell through to handleDataMsg and was logged as an unhandled message and dropped — nothing in the app accepted pasted text.

The login form was the worst of it: a password could not be pasted in at all.

Fix

bubbles' textinput already handles tea.PasteMsg, so routing is enough.

• Split updateCurrentView out of handleViewKeys so non-key messages reach the same views without being retyped as key presses.
• Forward paste to the login form, connection form and command palette.
• Table views accept paste only while their filter input is focused — otherwise pasted text would be read as a burst of navigation keys.
• The login form stays frozen while a keygen is in flight, matching the existing key handling.
• PasteStartMsg/PasteEndMsg are matched as no-ops so the bracketing markers don't trip the unhandled-message warning.

Verification

Reproduced and verified against a live PA-440 (PAN-OS 11.2.10-h8) by driving the TUI under a pty and sending a real ESC[200~ … ESC[201~ sequence:

• Before: password field stayed on its placeholder, zero characters entered.
• After: field shows 8 masked characters and the pasted password authenticates successfully.

Unit tests cover paste into each login field and that pasting is ignored while authenticating.

gofmt, go vet, golangci-lint (0 issues) and go test -race ./... all clean.