Plugin TUI: Field interfaces — inline + overlay (Phase 5)

[hegner123]

Plugin Field Interfaces

Implements PluginFieldBubble and PluginFieldOverlay so plugins can provide custom field editors in the TUI content form dialog.

Plan: ai/plans/plugin/PLUGIN_TUI_SCREENS.md — Phase 5

Inline Mode

• PluginFieldBubble implementing FieldBubble
• Renders single primitive within field row (1-5 lines)
• Keys forwarded only when focused; tab/shift-tab/esc intercepted by form

Overlay Mode

• PluginFieldOverlay implementing ModalOverlay
• Opened on enter, renders full-screen grid layout
• Captures all keys until commit/cancel

Files

• internal/tui/bubble_plugin.go — PluginFieldBubble
• internal/tui/overlay_plugin.go — PluginFieldOverlay

Key behaviors

• commit action → update field value and close
• cancel action → close without changing value
• Coroutine lifecycle tied to content form dialog
• Register in type_registry as plugin field type
• Wire into resolveFieldInput

Depends on

• Plugin TUI: Standalone screens + async data (Phases 3-4) #231 (Standalone screens + async data)