feat(scheduler-sim-repl-verbosity): task 7.2 - implement resource formatting helpers

Implements repl_is_bytes_valued_resource()/repl_format_bytes_human()
(mirroring xce_test's confirmed is_bytes_valued_resource()/
format_bytes_human() precedent exactly) and the units_mode setting
(explicitly defaulted to both, not left to zero-init) wired into
set units raw|human|both alongside the existing set speed/output/verify
branches (Requirements 6.1-6.3). All 8 of task 7.1's tests pass.

Split repl_format_ts_human(), the Jobid Range Compressor (task 1.2),
and these two new helpers out of repl.c into a new repl_fmt.c: adding
them in place pushed repl.c to 929 lines (16.1% over the 800-line
cap), and unlike task 6.2's single-function split attempt (which
didn't even achieve compliance), bundling these three pure-formatter
groups together does - repl.c settles at 587 lines, repl_fmt.c at 402,
both comfortably under cap. Required a matching #include line in the
20 test files that white-box #include repl.c, plus extending
test_sim_isolation.c's forbidden-include/symbol scan to cover the new
file, following the repl_rollup.c split precedent from task 2.2.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YAWMhfRJFnmmnG8h97yUDd

src/scheduler/testsuite/meson.build

@@ -628,6 +628,9 @@ sched_sim_isolation_test = executable(
              '-DXCE_SIM_REPL_ROLLUP_C_PATH="'
              + (meson.current_source_dir() / '..' / 'src' / 'repl_rollup.c')
              + '"',
+             '-DXCE_SIM_REPL_FMT_C_PATH="'
+             + (meson.current_source_dir() / '..' / 'src' / 'repl_fmt.c')
+             + '"',
              '-DXCE_SIM_LIB_PATH="'
              + sched_sim_isolation_lib.full_path()
              + '"'],