ST code file saving - with V4.1

[ph1lj-6321]

Uhm, having some issues when trying to rename an ST code file - it will let me alter the name, but NOT save it - always returns to the name 'main'.

[JoaoGSP]

Verified resolved on main. ✅

How: This was caused by a v3-era guard in the XML generator that returned "Main POU not found" whenever no program POU was named main — so renaming the template-seeded "main" POU failed and the name snapped back. That guard has been removed (src/backend/shared/utils/PLC/xml-generator.ts), and updatePouName now cascades the rename into the configuration's instances[] so the IEC entry-program binding follows the new name. The same fix also rekeys LD/FBD canvas flows so graphical POUs keep their rungs through a rename.

Fix reference: commit 65be936a6 ("fix(rename): drop "main" POU restriction + carry LD/FBD rungs through rename"), merged into main via PR #795 on 2026-06-04.

Verified: static analysis of origin/main as of 4f76e93df, on 2026-06-17.

Closing as resolved. Note this shipped after V4.1, so updating to the latest build is needed. If you can still reproduce this on the latest build, please comment and we'll reopen.