Major documentation updates based on community feedback (Nov 2025)

Applied comprehensive corrections from Discord community (DeathStalker, Astrocast,
and others) to fix inaccuracies, remove outdated procedures, and improve readability.

CRITICAL SAFETY FIXES:
- IOMMU: Changed from "optional" to "MUST disable" across all docs
- Removed dangerous `amd_iommu=on` kernel parameter (causes crashes)
- Added danger warnings that IOMMU is broken on BC-250

BIOS & VRAM FIXES:
- Fixed BIOS flashing guide: removed fake "ZIP file" references
- Added link to actual flasher utility (separate from ROM download)
- Removed made-up Windows utility steps, added real ASRock method
- Removed AMIBCP/Smokeless section (not used, P5.00_clv has all unlocked)
- VRAM docs: reduced verbosity by 40%, emphasized 512MB is DYNAMIC
- Added ZRAM conflict warning (crashes in RDR2 with dynamic VRAM)

COOLING & HARDWARE:
- Removed impractical fin cutting/screwing instructions
- Removed J4003 header references (not for normal users)
- Added tower cooler downside (must cool VRAMs separately)
- Static pressure already correct at 6.9 mm H2O

LINUX DISTRIBUTION UPDATES:
- Fedora: Removed outdated setup script, Mesa 25.1 now in repos
- Fedora: nomodeset no longer needed on 42/43 with working kernels
- Bazzite: Removed "on steroids" section (patch included by default)
- CachyOS: Simplified from custom ISO to standard installation
- Updated KDE vs GNOME: GNOME recommended for stability (6 changes)
- SteamOS/Ubuntu: Already added in previous commit (verified)

GOVERNOR & DRIVERS:
- Prioritized COPR installation over building from source
- Added @exotic-soc/oberon-governor and filippor/bazzite repos
- Display adapters: Now recommend PASSIVE (audio works) over active

IMPOSSIBLE FEATURES REMOVED:
- Fortnite: Clarified it cannot run (Easy Anti-Cheat)
- ROCm training: Corrected to "experimental/limited" (doesn't work)

Desktop Environment: GNOME now recommended over KDE for stability
(KDE had Qt RDSEED bug, now fixed but GNOME more tested)

Files modified: 14
Community credits: DeathStalker, Astrocast, legodude

docs/troubleshooting/display.md

@@ -390,7 +390,7 @@ Reduce frequency or increase voltage in governor config.
 - Display works initially then fails
 
 **Cause:**
-IOMMU (AMD's virtualization feature) can interfere with display output on some adapters.
+IOMMU is broken on BC-250 and **MUST be disabled**. It causes display failures, black screens, and system instability.
 
 **Solution:**
 
@@ -408,8 +408,8 @@ dmesg | grep -i iommu
 # Should show "AMD-Vi: AMD IOMMU disabled"
 ```
 
-!!!info "When to Enable IOMMU"
-    Only enable IOMMU if you're doing GPU passthrough for virtualization. For normal use, keep it disabled.
+!!! danger "IOMMU is Broken on BC-250"
+    IOMMU is broken on BC-250 and causes display issues, black screens, and system instability. **ALWAYS keep it disabled**. Even for virtualization, IOMMU does not work reliably on this board.
 
 ---