FABRIC-3.md: version correction -- LITHOS_VERSION back to 2.0.0, plus a rename-gap fix

LITHOS_VERSION 2.0.1 was premature: per this project's own versioning
policy, 2.0.1 claims SER5 hardware-track progress (RDRAND backend +
thumbdrive image) that was never actually verified on real hardware --
that verification is FABRIC-3.md's own open topic. Reset to 2.0.0
(still a QEMU-only release, correctly). Verified 3-arch boot shows
"LithosAnanke v2.0.0" in each serial log directly, not assumed from the
Makefile edit alone.

Also closes a real gap found in today's earlier FABRIC-series rename:
Makefile.starkernel, Kconfig.kernel, scripts/bleach_zuse_img.sh, four
proof/*.thy files, and isr.S were never swept -- the original file list
only matched *.md/*.c/*.h/*.4th, silently skipping every other
extension. Fixed with the same safe placeholder substitution.
.claude/settings.local.json's historical permission-grant log and
ClaudeEXPORT/'s frozen export were deliberately left untouched.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019YcT3H2PQeyujrzjqS3Var

src/starkernel/arch/amd64/isr.S

@@ -157,7 +157,7 @@ isr_stub32:
     jmp isr_common_entry
 
 /* Stub for i8042 keyboard IRQ1, routed via I/O APIC to vector 0x21 = 33
- * (item 4.3.5, FABRIC.md §27.5). Before this stub existed, vector 33 fell
+ * (item 4.3.5, FABRIC-0.md §27.5). Before this stub existed, vector 33 fell
  * through to isr_stub_default below, which unconditionally reports "255"
  * regardless of which IDT slot actually fired -- the CPU legitimately took
  * IDT[33] (confirmed via the LAPIC's own ISR register), but isr_common_handler