Add interactive chart time navigation

[xptea]

Summary

• add a repository-level AGENTS.md with build, terminal, safety, and release guidance
• retain 14,400 timestamped chart samples and decouple the visible time span from terminal width
• add mouse-wheel zoom, Shift+wheel and keyboard history panning, live/oldest navigation, and in-chart point tooltips
• extend ConPTY coverage for zoom, pan, hover, resize, and bounded repaint behavior

Local verification

• build.ps1 -Configuration Debug -Test
• build.ps1 -Configuration Release -Test
• build.ps1 -Configuration Sanitize -Test -OutputName vgpu-mon-asan
• analyze.ps1
• tools/verify-pe.ps1
• five repeated ConPTY chart interaction runs
• portable ZIP, installer, version manifest, and SHA-256 metadata built successfully

The local installer lifecycle test was intentionally not run because it refuses to overwrite the existing user installation. CI runs that lifecycle on a clean Windows runner.