Rename FABRIC series: FABRIC.md->0, FABRIC-2.md->1, FABRIC-3.md->2, FABRIC-4.md unchanged

FABRIC.md -> FABRIC-0.md
FABRIC-2.md -> FABRIC-1.md
FABRIC-3.md -> FABRIC-2.md (the current/living document)
FABRIC-4.md unchanged (new #3 to follow separately)

Every cross-reference repo-wide updated to match, including doc-comment
citations inside kernel source (.c/.h) files -- done via an ordered
placeholder substitution (FABRIC-3.md->placeholder2, FABRIC-2.md->
placeholder1, FABRIC.md->placeholder0, then placeholders resolved to
final names) in a single pass per file to avoid double-shifting
already-renamed references.

One line in capsules/font.4th grew past the 64-char block-format limit
as a side effect of the longer filename; shortened it and reverified
with mkcapsule --lint (34/34 pass) before rebuilding.

Verified 3-arch boot to ok> (amd64/aarch64/riscv64, each in the
foreground) after the fix; logs and DoE CSVs from this session's
verification runs included per this repo's own audit-artifact
convention.

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

ROADMAP.md

@@ -6,7 +6,7 @@
 > Tripod/Stadium/word-level ACL existed, and before "Phase 1 Starting (HAL)" had any of the
 > meaning it has now. Kept for historical record only. For current status, see
 > `docs/lithosananke/ROADMAP.md` (repo-specific, LithosAnanke roadmap) and
-> `FABRIC.md`/`FABRIC-2.md`/`FABRIC-3.md` (design history and current work) — not this
+> `FABRIC-0.md`/`FABRIC-1.md`/`FABRIC-2.md` (design history and current work) — not this
 > document.
 
 **Version**: 1.0