fix: client: terminal: refit after show

[giulianoliker]

Fixes the terminal opening at the wrong size, the known issue noted in #484 (Cyan-Sinko theme).

Cause: terminal.js and terminal-run.js create gritty on document.body. Gritty runs xterm's fit addon once at that point, against the body, and refits only on window resize. View.show then moves the terminal into the modal. Nothing refits it there, so its rows and columns still match the body, not the view.

With light and dark the body and the view happen to give the same size, so the problem doesn't show. I measured both at 1920×1080, 1440×900, 1280×720, 1024×768, 880×800, 768×1024, 600×900 and 375×812, and the terminal fit every time. With a different page layout, such as the Cyan-Sinko theme, the terminal opens up to 252px taller than the view (bottom rows cut off) and uses only about 60% of the width, until the window is resized.

Fix: dispatch resize in afterShow, so gritty refits to the view. Gritty keeps its fit addon private, so this triggers the refit through gritty's own resize listener. Cloud Commander's own resize handler also runs; it acts only below the one-panel width when the right panel is active, which is already the state there.

Since gritty is also part of the Cloud Commander project, an alternative would be a small public fit() in gritty instead of dispatching resize. Happy to do it that way if you prefer.

	Before	After
Cyan-Sinko, 1440×900	1020px of rows in an 828px view	816px of rows in 828px
light, 1440×900	860 in 860	860 in 860 (unchanged)

• commit message named according to Contributing Guide
• npm run fix:lint is OK (it leaves no changes)
• npm test is OK (364/364, on Linux with Node 24)

Built with help from Claude Code; I reviewed and tested it myself.