Refactor: Chipset architecture, remove supported/status gatekeeping

- PlatformType → Chipset enum (MediaTek, Renesas)
- unlock_mode + unlock_buf_id stored in profile, not derived from enum
- Removed ReadinessStatus, supported field, needs_flash — library is agnostic
- Removed DriveMatch/Flashable — if we have a profile, try unlock
- profiles.json: chipset + unlock_mode + unlock_buf_id, no program/supported
- mt1959.rs reads mode/buf_id from profile fields directly
- Tests: find_known_drive, find_unknown_drive

src/bin/freemkv_info.rs

@@ -100,7 +100,7 @@ fn print_human(
         println!();
         match matched {
             Some(p) => {
-                println!("Profile:  FOUND ({})", p.platform.name());
+                println!("Profile:  FOUND ({})", p.chipset.name());
                 println!("Raw Read: Supported");
             }
             None => {