refactor(generated): move scaffold into generated directory

[MintsInc]

Summary

Move the generated-command scaffold into an isolated directory for generated modules.

Changes

• Move src/generated.rs to src/generated/mod.rs
• Update the scaffold comment to describe generated modules within the directory
• Keep the existing mod generated; integration and CLI behavior unchanged

This layout keeps generated command modules out of the crate root and separate from hand-written modules under src/commands/. Moving the existing scaffold also prevents src/generated.rs and src/generated/mod.rs from coexisting and causing Rust error E0761.

Testing

• cargo build
• cargo fmt --check
• cargo clippy --all-targets -- -D warnings
• cargo test -- --test-threads=1 — 2,003 passed
• Confirmed pup --help contains no generated subcommand
• Browser WASM build not run locally because the wasm32-unknown-unknown target is unavailable