Fix dashboard picker not resizing on terminal resize

[lsegal]

Root cause

glorp ui shows an interactive picker (dashboardPicker in uicmd.go) when more than one glorp dashboard is running locally. Unlike the main terminal dashboard (ui.go), the picker never handled tea.WindowSizeMsg at all, so it never learned the terminal's width. Its labels (port %d — target1, target2, ... (N running, M queued)) can be long, and resizing the terminal — narrower or wider — had no effect on the rendered output: the picker simply never adapted, which matches the reported "tui not resizing on term resize" behavior.

Change

• dashboardPicker now tracks a width field and updates it on tea.WindowSizeMsg.
• View() truncates each dashboard's label to fit the current terminal width, reusing the existing truncate helper already used by the main dashboard.

Verification

Before the fix, the picker's label ignored terminal width entirely:

--- before any resize (width=0, unclamped) ---
Select a glorp dashboard to open

> port 8765 — lsegal/glorp, lsegal/glorp-www, lsegal/glorp-docs (3 running, 5 queued)

↑/↓ move · enter open · q cancel

After the fix, resizing the terminal to 30 columns truncates the label to fit:

--- after resizing terminal to 30 cells wide ---
Select a glorp dashboard to open

> port 8765 — lsegal/glorp,...

↑/↓ move · enter open · q cancel

Tests

• Added TestDashboardPickerResizesToTerminalWidth covering both narrowing (label truncates, no line exceeds the new width) and widening (full label reappears) after a resize.
• go vet ./... and go test ./... pass.

Changelog

Added an ## Unreleased entry in CHANGELOG.md.

UI capture

This is a terminal (non-browser) interface with no browser-automation tooling available in this environment. Text captures of the picker's rendered output before and after the fix are included above per repository convention.

Closes #651

Agents: claude-code (claude-sonnet-5)