feat(scheduler-sim-diagnostics): wire info limit into REPL dispatch

repl_cmd_info() now recognizes "limit" as an info subcommand, routing to the
already-implemented and tested repl_info_limit() with the same ntok<3 usage
guard shape as the queue/worker/resource branches. Usage string and help
text updated to list it. repl_info_limit()'s own body is untouched -- this
is a pure, additive dispatch-wiring change. Two new tests drive it through
the real repl_dispatch() entry point (not a direct call) for both `info
limit <name>` and `info limit all`.

`info limit <name|all>` is now reachable from a live REPL session --
scheduler-sim-diagnostics' first capability is functionally complete.
Remaining: task 5 (determinism/regression validation).

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

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

@@ -42,7 +42,7 @@
   - Observable: a limit matched against jobs on two distinct hosts shows two separate per-host usage lines each labeled with its own scope values, and a third configured-but-untouched host shows no line at all
   - _Requirements: 1.4, 2.1, 2.2, 2.3, 3.1, 3.2, 3.4_
 
-- [ ] 4. Register `info limit` as a recognized `info` subcommand
+- [x] 4. Register `info limit` as a recognized `info` subcommand
   - New `else if (strcmp(tokens[1], "limit") == 0)` branch in `repl_cmd_info()` (`repl_info.c`) routes to `repl_info_limit()`; usage-string literal updated to list `limit` alongside the existing subcommands
   - `test_repl_limit_table.c` gains a full dispatch-round-trip test (via `repl_dispatch()`, not a direct call) for both `info limit <name>` and `info limit all`
   - Observable: `info limit <name>` and `info limit all` both work when typed as real REPL input (through `repl_dispatch()`), and `help`/usage output lists the new subcommand