refactor: extract profile commands from main.rs to dedicated module (#403)

- Create commands/profile.rs with all profile command handlers
- Move 660 lines of profile logic out of main.rs
- Reduce main.rs from 1,589 lines to 929 lines (41.5% reduction)
- Split into focused handlers: list, path, show, set, remove, validate, default-enterprise, default-cloud
- Update commands/mod.rs to include profile module
- Remove unused Context import from main.rs
- All 45 tests passing
- No clippy warnings

Main.rs now focuses on CLI parsing, initialization, and command routing.

Closes #402

Author: joshrotenberg

crates/redisctl/src/commands/mod.rs

@@ -4,3 +4,4 @@ pub mod api;
 pub mod cloud;
 pub mod enterprise;
 pub mod files_key;
+pub mod profile;