feat(scheduler-sim-repl-verbosity): task 1.2 - implement job identifier range compression

Implements repl_fmt_jobid_range() in repl.c (per design.md's "no new
production .c file" commitment), grouping job-array identifiers by base
and compressing contiguous index runs into [lo-hi] ranges. All 5 of task
1.1's RED-phase tests now pass.

Went through one review round: an initial GREEN implementation placed
the function in a new file (repl_jobid_range.c) to sidestep a linker
issue in the lean test target from task 1.1. Review found and verified
a cleaner fix: link the test against the full scheduler_srcs object list
(mirroring the existing sched_scheduler_connect_test precedent), which
resolves the same symbols without a new file. Remediated accordingly;
bug-1762 in buglog.json documents the investigation.

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

.kiro/specs/scheduler-sim-repl-verbosity/tasks.md

@@ -6,7 +6,7 @@
   - Observable: the new test cases execute and fail against the current codebase, which has no compression behavior yet
   - _Requirements: 4.1, 4.2, 4.3, 4.4, 4.5_
 
-- [ ] 1.2 Implement job identifier range compression so the new tests pass
+- [x] 1.2 Implement job identifier range compression so the new tests pass
   - Group identifiers by their shared array submission and render contiguous index runs as a single compressed range, comma-joining non-contiguous runs
   - Never drop or fabricate an identifier, and fail safely (without truncating or crashing) when the output buffer is too small
   - Observable: all tests from 1.1 pass; the helper is ready for the event-echo and round-summary work to adopt