FABRIC-2.md: record verified clean Isabelle/HOL rebuild (52 theories, genuinely green)

Ran isabelle build -c (clean, forces fresh rebuild bypassing any cached
heap) for real, per the agreed sequencing (code sweeps -> HOL green ->
POST coverage). All 52 theories rebuilt from scratch in 42s, zero
errors/failures/sorry/oops anywhere in the log -- upgrades the earlier
entry's static-inspection-only inference to an actual verified result.

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

FABRIC-2.md

@@ -1414,6 +1414,25 @@ reconciliation above for the Isabelle/HOL findings):
 
 **Not covered by this pass, honestly:** non-static dead-function cross-referencing (needs
 symbol-by-symbol call-site verification across ~150+ C files, out of budget), C99 smell
-categories beyond warnings (magic numbers, function length, duplication), actually running
-`isabelle build` end-to-end (static inspection only), and the bulk of `docs/formal/`/
-`docs/patent/`/`docs/working/` beyond the specific files named above.
+categories beyond warnings (magic numbers, function length, duplication), and the bulk of
+`docs/formal/`/`docs/patent/`/`docs/working/` beyond the specific files named above.
+
+**Addendum, same evening: `isabelle build` actually run end-to-end, genuinely green.** The
+item above was flagged as "static inspection only, not run" — run for real immediately
+after, per Captain Bob's explicit sequencing ("finish code sweeps, then do the Isabelle/HOL
+stuff... after HOL is green we update POST testing"). Memory-safety procedure from
+`feedback_isabelle_build_memory_safe.md` followed: `-o threads=1`, backgrounded, watched via
+the `Monitor` tool rather than manual polling. A local Gitea Actions CI run (`act`, triggered
+automatically by this session's earlier pushes) was caught actively running a
+`git checkout --force` at the same time — investigated before proceeding: it operates in its
+own fully isolated clone (`~/.cache/act/.../hostexecutor/`), never touches this working tree,
+confirmed harmless, and the session waited for it to finish before starting the memory-heavy
+build anyway rather than stack two heavy processes.
+
+First invocation without `-c` finished in 4 seconds — a cache hit against an already-built
+heap image, not proof. Re-run with `-c` (clean, forces a genuine fresh rebuild, discarding any
+cached session heap): **all 52 theories rebuilt from scratch, 0:00:42 total elapsed, zero
+occurrences of `error`/`fail`/`sorry`/`oops`/`exception`/`abort` anywhere in the full build
+log.** This is the real, current, verified state — not inferred from file/`ROOT` consistency
+as the earlier entry above had to settle for. The 52-theory count itself (vs. `FINDINGS.md`'s
+stale "53") is confirmed correct by this run too.