FABRIC.md: mark 4.5 as blocking priority over all other punch-list work

Captain Bob 2026-08-11: no other item gets worked until 4.5a-4.5f (the
-O0-kernel fix) are done.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

FABRIC.md

@@ -5332,7 +5332,9 @@ document and committing that amendment as its own item.*
   *Refs:* §27.8, CLAUDE.md ACL section (Phase 8).
 
 - [ ] **4.5 — URGENT, flagged by Captain Bob 2026-08-11: the kernel build has never used any
-  compiler optimization.** Found while investigating why moving `console_fb_init()` earlier
+  compiler optimization.** **Blocking priority, set by Captain Bob 2026-08-11: no other
+  punch-list item is worked until 4.5a–4.5f are done**, ahead of whatever would otherwise
+  come next in sequence. Found while investigating why moving `console_fb_init()` earlier
   in boot (4.4g) stalled boot indefinitely (12,700+ lines logged, still running after 3
   minutes vs. a normal few-second boot). Cross-cutting — affects the entire kernel, not just
   Console work — recorded here because it was found during Phase 4 and blocks 4.4g, but it