feat(sp24): register cyclone reissue-claims CLI subcommand

Adds @main.command('reissue-claims') to cli.py following the
cyclone-cli conventions:
  - long-form flags only (no positional args; per-click-confirm-safe)
  - exit codes 0 / 1 / 2 with documented semantics in the docstring
  - click.echo(..., err=True) for errors
  - setup_logging() called per-invocation so --log-level overrides
    the group default

The command body is a thin shell over cyclone.reissue:
  1. ig_correctness_check (refuses to run if the SP24 guard trips)
  2. parse_inputs → emit_outputs → write_summary_sidecar
  3. Optional zip_outputs to --zip-output
  4. Final click.echo summary line.

Live-test on the 2026-07-08 dzinesco July-8 batch produces
358 X12 files, 378078 bytes total, zip 245829 bytes (matches the
original scripts/reissue_claims.py exactly). All 358 emitted files
have HL*2 child_count=0 and no HL*3 segment — the IG-correct shape
for SBR02='18'.

backend/src/cyclone/cli.py

@@ -2050,5 +2050,234 @@ def rebill_from_835(
     click.echo(f"Wrote {n} summary rows to {summary_path}")
 
 
+# ---------------------------------------------------------------------------
+# SP24: `cyclone reissue-claims` — offline 837P reissue workflow.
+#
+# Re-parses raw 837P files under --input-dir, validates each parsed
+# claim against the per-payer config, and emits one IG-correct
+# single-claim X12 file per claim under --output-root/<date>/<pipeline>/.
+# Optionally zips the output to --zip-output.
+#
+# The IG-correctness guard (`ig_correctness_check`) reads
+# `serialize_837.PATIENT_LOOP_DEFAULT_INCLUDED` on every invocation and
+# refuses to run if it ever flips back to True — see the SP24 spec for
+# the regression story behind the constant.
+#
+# Exit codes:
+#   0  — every file emitted cleanly (or with per-file warnings only)
+#   1  — IG-correctness guard tripped OR an unexpected error
+#   2  — parse / validation failure on a file AND zero claims survived
+# ---------------------------------------------------------------------------
+
+
+@main.command("reissue-claims")
+@click.option(
+    "--input-dir",
+    type=click.Path(exists=True, file_okay=False, path_type=Path),
+    required=True,
+    help="Directory holding raw 837P files (*.x12, *.txt, *.edi).",
+)
+@click.option(
+    "--output-root",
+    type=click.Path(file_okay=False, path_type=Path),
+    default=Path("dev/rebills"),
+    show_default=True,
+    help="Root dir; output lands in <output-root>/<date>/<pipeline>/.",
+)
+@click.option(
+    "--date",
+    default=None,
+    help="YYYY-MM-DD subfolder under --output-root (default: today MT).",
+)
+@click.option(
+    "--pipeline",
+    default="initial",
+    show_default=True,
+    help="Pipeline subfolder name (e.g. 'initial', 'resubmit', 'corrected-v2').",
+)
+@click.option(
+    "--payer",
+    default="co_medicaid",
+    show_default=True,
+    help="Payer config preset passed to the parser.",
+)
+@click.option(
+    "--sender-id",
+    default="11525703",
+    show_default=True,
+    help="ISA06 / GS02 — Dzinesco TPID.",
+)
+@click.option(
+    "--receiver-id",
+    default="COMEDASSISTPROG",
+    show_default=True,
+    help="ISA08 / GS03 — CO Medicaid.",
+)
+@click.option(
+    "--submitter-name",
+    default="Dzinesco",
+    show_default=True,
+)
+@click.option(
+    "--submitter-contact-name",
+    default="Tyler Martinez",
+    show_default=True,
+)
+@click.option(
+    "--submitter-contact-email",
+    default="tyler@dzinesco.com",
+    show_default=True,
+)
+@click.option(
+    "--receiver-name",
+    default="COLORADO MEDICAL ASSISTANCE PROGRAM",
+    show_default=True,
+)
+@click.option(
+    "--zip-output",
+    type=click.Path(file_okay=False, path_type=Path),
+    default=None,
+    help="If set, zip all emitted X12 files to this path.",
+)
+@click.option(
+    "--no-clean",
+    is_flag=True,
+    default=False,
+    help="Don't wipe prior .x12 outputs in the pipeline subdir before writing.",
+)
+@click.option(
+    "--log-level",
+    default="INFO",
+    show_default=True,
+    type=click.Choice(["DEBUG", "INFO", "WARNING", "ERROR"]),
+)
+def reissue_claims(
+    input_dir: Path,
+    output_root: Path,
+    date: str | None,
+    pipeline: str,
+    payer: str,
+    sender_id: str,
+    receiver_id: str,
+    submitter_name: str,
+    submitter_contact_name: str,
+    submitter_contact_email: str,
+    receiver_name: str,
+    zip_output: Path | None,
+    no_clean: bool,
+    log_level: str,
+) -> None:
+    """Re-parse raw 837P files and emit one IG-correct single-claim X12 per claim (SP24).
+
+    Workflow:
+      1. Parse every *.x12 / *.txt / *.edi under --input-dir.
+      2. Validate each parsed claim; skip claims with hard errors.
+      3. Serialize each surviving claim via the IG-correct serializer.
+      4. Write one X12 file per claim under
+         --output-root/<date>/<pipeline>/ using HCPF-spec filenames.
+      5. Optionally zip the output to --zip-output.
+
+    Exit codes: 0 success (some per-file warnings are non-fatal);
+    1 IG-correctness guard tripped or unexpected error;
+    2 parse / validation failure on a file AND zero claims survived.
+    """
+    # SP18: re-run so --log-level overrides the group default.
+    setup_logging(level=log_level)
+
+    from cyclone.reissue import (
+        emit_outputs,
+        ig_correctness_check,
+        parse_inputs,
+        write_summary_sidecar,
+        zip_outputs,
+    )
+    from cyclone.parsers.payer import PayerConfig
+
+    log = logging.getLogger("reissue-claims")
+
+    # 0. IG-correctness guard. Fires on every invocation — cheap (one
+    # constant read) and the only defense against the 999 rejection
+    # root cause coming back via a future refactor.
+    if not ig_correctness_check(logger=log):
+        click.echo(
+            "REFUSING to run: PATIENT_LOOP_DEFAULT_INCLUDED is True; "
+            "the 2000C patient loop is forbidden when SBR02='18'. "
+            "Restore the IG-correct default (False) in serialize_837.py.",
+            err=True,
+        )
+        sys.exit(1)
+
+    # 1. Payer config factory. Keep this tiny — extend as more
+    #    payer presets land in PayerConfig.
+    payer_factories = {
+        "co_medicaid": PayerConfig.co_medicaid,
+        "generic_837p": PayerConfig.generic_837p,
+    }
+    if payer not in payer_factories:
+        raise click.BadParameter(
+            f"Unknown payer {payer!r}. Choose from: {', '.join(payer_factories)}"
+        )
+    payer_config = payer_factories[payer]()
+
+    # 2. Output directory layout.
+    date_label = date or datetime.now().strftime("%Y-%m-%d")
+    out_dir = output_root / date_label / pipeline
+    if out_dir.exists() and not no_clean:
+        # Clean only the per-claim X12 files + summary; leave any
+        # sibling artifacts (logs, sidecars) alone.
+        for p in out_dir.glob("tp*.x12"):
+            p.unlink()
+        log.info("cleaned prior .x12 outputs under %s", out_dir)
+
+    # 3. Parse → 4. Serialize → 5. Zip.
+    log.info("parse: input_dir=%s payer=%s", input_dir, payer)
+    claims, parse_errors = parse_inputs(input_dir, payer_config)
+    log.info(
+        "parse: %d claims read, %d file-level errors",
+        len(claims),
+        len(parse_errors),
+    )
+    for src, err in parse_errors[:10]:
+        log.warning("  %s: %s", src, err)
+    if parse_errors and not claims:
+        click.echo(
+            f"PARSE FAILED: zero claims survived; first error: {parse_errors[0][1]}",
+            err=True,
+        )
+        sys.exit(2)
+
+    log.info("serialize: output_dir=%s", out_dir)
+    written = emit_outputs(
+        claims,
+        payer_config=payer_config,
+        output_dir=out_dir,
+        sender_id=sender_id,
+        receiver_id=receiver_id,
+        submitter_name=submitter_name,
+        submitter_contact_name=submitter_contact_name,
+        submitter_contact_email=submitter_contact_email,
+        receiver_name=receiver_name,
+    )
+
+    summary_path = write_summary_sidecar(claims, written, out_dir)
+    total_bytes = sum(p.stat().st_size for p in written)
+    log.info(
+        "serialize: %d files, %d bytes, summary=%s",
+        len(written),
+        total_bytes,
+        summary_path,
+    )
+
+    if zip_output:
+        zip_outputs(written, zip_output)
+        log.info("zip: %s (%d bytes)", zip_output, zip_output.stat().st_size)
+
+    click.echo(
+        f"DONE files={len(written)} errors={len(parse_errors)} out={out_dir}"
+    )
+    if parse_errors:
+        sys.exit(2)
+
+
 if __name__ == "__main__":
     main()