CAMEL-23420: Add diagram modes and fullscreen scrolling to TUI monitor

[davsclaus]

Summary

• Add separate d (image diagram) and D (text diagram) shortcuts in the TUI monitor Routes tab
• When terminal doesn't support images, d shows a message suggesting Shift+D instead of silently falling back to ASCII
• Both diagram modes open in fullscreen with a live-updating route info header and TamboUI Scrollbar widgets for vertical and horizontal scrolling
• Image diagram uses ImageData.crop() for viewport-based scrolling with crop caching to avoid unnecessary recomputation
• Image is scaled to 50% to fit better in terminal cells
• Reduced refresh rate (1s) and skip re-render on idle ticks when showing image diagram to prevent flicker
• Footer shows the matching close key (d or D) depending on how the diagram was opened

Test plan

• Run camel monitor against a running Camel integration
• Press D on the Routes tab — verify fullscreen text diagram with route header and scrollbars
• Press d on a terminal with image support — verify fullscreen image diagram with scrollbars, no flickering
• Verify arrow keys scroll vertically and horizontally in both modes, PgUp/PgDn for page scrolling
• Verify the route info header updates live (e.g., total count increases)
• Press d on a terminal without image support — verify it shows the "use Shift+D" message
• Press Esc or the matching key to close the diagram

Claude Code on behalf of Claus Ibsen

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🧪 CI tested the following changed modules:

• dsl/camel-jbang/camel-jbang-plugin-tui

All tested modules (2 modules)

• Camel :: JBang :: Plugin :: TUI
• Camel :: Launcher :: Container

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