test(scheduler-sim-diagnostics): verify info limit is read-only and deterministic

Four new tests in test_repl_limit_table.c close out Requirement 5:
- test_info_limit_never_mutates_global_limit_config_or_accounting_state /
  ..._host_scoped_... : snapshot a matched limit's config fields and its
  vres capacity/in-use zarray entries (both pointer identity and value)
  before and after repeated info limit calls; asserts byte-identical state
  and byte-identical repeated stdout output.
- test_info_limit_on_empty_registry_is_repeatable_and_never_registers_plugin:
  confirms info limit never causes the plugin to become spuriously
  registered as a side effect of being queried.
- test_repl_step_continue_with_info_limit_interleaved_matches_baseline_decision_sequence:
  a step/continue sequence run twice (once with info limit interleaved, once
  without) produces an identical decision sequence.

Verified via real mutation testing: three targeted fake mutations were
temporarily applied to repl_info.c, confirmed each new test fails exactly as
predicted, then cleanly reverted (repl_info.c shows zero diff from HEAD).
Zero production code changed -- this is a test-only validation task. Full
14-binary regression sweep + 78/78 meson aggregate confirm zero impact on
any pre-existing info subcommand (Requirement 5.3).

This closes out scheduler-sim-diagnostics' first capability (limit
inspection, Requirements 1-5) end to end.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RLSNJhNoULvVcUhXEFafQC

.kiro/specs/scheduler-sim-diagnostics/tasks.md

@@ -49,7 +49,7 @@
   - _Requirements: 4.1, 4.2_
   - _Depends: 2.1, 3.1, 3.2_
 
-- [ ] 5. Verify no mutation, replay determinism, and existing-subcommand regression
+- [x] 5. Verify no mutation, replay determinism, and existing-subcommand regression
   - Test: displaying limit information never alters configuration, accounting state, or scheduling decisions (assert config/accounting untouched before vs. after)
   - Test: a replay run twice — once with `info limit` issued mid-session, once without — produces identical scheduling decisions and identical final accounted state
   - Full existing `info` subcommand test suite (job/queue/worker/resource/summary) re-run to confirm zero output changes from this addition