Add tuirec recording guide and hero-gif docs

[tig]

Process documentation for capturing GIFs/recordings of Terminal.Gui apps and scenarios.

Changes

• hero-gif.md — minimal root-level pointer to the recording guide
• Scripts/tuirec.md — comprehensive recording guide covering:
  • Recommended workflow (build → launch → record → export → validate)
  • Practical guidance for AI agents
  • Validation checklist
  • TBD sections for UICatalog scenarios, EnableForDesign views, and standalone example apps

These docs support the hero-GIF workflow discussed in #5393.

[tig]

Superseded by PR #5393 which consolidates all Spectre interop work.

[tig]

Feedback from using tuirec guidance to record SpectreView scenario

The recording succeeded first try using ScenarioRunner + tuirec record. Here are suggestions for the TBD sections:

For "Recording UICatalog Scenarios" section:

• Document that ScenarioRunner run <Name> is the correct binary/args pattern
• Note: build ScenarioRunner first (dotnet build Examples/ScenarioRunner)
• Recommend --startup-delay 1500 for TG apps (they need time to render initial frame)
• Show the standard pattern:

  tuirec record \
    --binary Examples/ScenarioRunner/bin/Debug/net10.0/ScenarioRunner \
    --args run,<ScenarioName> \
    --name <scenario-kebab> \
    --show-command "dotnet run -- run <Name>" \
    --cols 100 --rows 30 \
    --startup-delay 1500 \
    --keystrokes "wait:1500,<script>,Ctrl+Q"
  

• OptionSelector navigation uses CursorDown/CursorUp key names
• Add --drain 500 to capture the final frame before exit
• Output GIF should go to Examples/UICatalog/Scenarios/<ScenarioName>.gif

For "Recording Individual View Sub-classes with EnableForDesign":

• Needs a dedicated lightweight runner that instantiates a single View with EnableForDesign
• Not yet clear how this would be scripted - may need a new mini-app

For "Recording Standalone Example Apps":

• Similar to ScenarioRunner but --binary points directly at the example exe
• Example: --binary Examples/Example/bin/Debug/net10.0/Example