build: replace argument dispatch and retain source-bound verification

Replace argument recovery with direct build targets. Run host, target,
board, coverage, Miri and selected Kani checks while retaining source
identities, logs and artifacts, including failed attempts.

Keep the PID proof diagnostic exception explicit and match its exact
identity alongside passing contract assertions and covers.

Validation: final-source verification matrix, assembled workflow tests
and documentation build.

firmware/scripts/summarize-test-coverage.py

@@ -1,24 +1,16 @@
 #!/usr/bin/env python3
 """Summarize strict-core LCOV lines and LLVM JSON branches by source location.
 
-`llvm-cov` emits one coverage record for every generic monomorphization.  Its
-per-file totals add those records, which can report an uncovered duplicate even
-when the corresponding source line or branch has been exercised by another
-monomorphization.  This helper instead applies the gate to source locations:
+Merge generic monomorphizations by source location. A location is covered if
+any instance executed it:
 
-* a source line is identified by its LCOV `DA` file and line number;
-* a branch outcome is identified by its full source span; and
-* a location is covered when any matching monomorphization executed it.
+* lines use LCOV `DA` file and line numbers
+* branch outcomes use their full source spans
 
-JSON segments are deliberately not used as a line denominator: they mark LLVM
-instrumentation-region boundaries, not every source line represented by an
-LCOV `DA` record.  Replacing `DA` with segments would silently lower the strict
-line denominator.
+JSON segments mark instrumentation boundaries and omit some `DA` lines.
+Using them would undercount the line denominator.
 
-Macro-expansion records are deliberately rejected.  Their source span denotes
-the invocation, not necessarily the expanded predicate, so folding them into
-the source-level key would make the gate unsound.  Extend this helper with an
-explicit expansion identity before adding macro-expanded strict-core coverage.
+Reject macro expansions: invocation spans cannot distinguish expanded predicates.
 """
 
 from __future__ import annotations