feat: modern boxed help output for affine CLI

[dataCenter430]

closes : #344

Summary

• Add affine/cli/help.py with AffineHelpFormatter, AffineContext, and AffineGroup — a custom Click help formatter that renders fully-enclosed section boxes (┌─ Options ─┐ / │ ... │ / └───────────┘) with colored output on wide terminals (≥ 100 cols), and falls back to standard Click formatting on narrow terminals
• Bold-yellow Usage: + program name, dimmed args — matching btcli/gitt CLI style
• Cyan command/option names inside boxes
• Patch click.Context.make_formatter globally so every command (af get-envs --help, af validate --help, etc.) picks up the formatter without needing per-decorator changes
• Wire AffineGroup / AffineContext into main.py for the top-level cli and servers groups, and inject context_class into the imported db and miner_stats groups

Behaviour

Terminal width	Output
< 100 cols	Standard Click plain-text help (unchanged)
≥ 100 cols	Boxed sections, colored names, yellow Usage line

Files changed

• affine/cli/help.py — new file (formatter, context, group classes)
• affine/cli/main.py — import + wire-up (7 lines changed)

Before:

Afer:

[dataCenter430]

Hi, @angosr
Would you please review the PR when you have a chance?
Please provide me your feedback.

[dataCenter430]

Hi, @angosr
Would you please review this PR?