feat(release): v0.2.0 — batch 837 export, ClaimCard, theme tokens

Backend:

- New POST /api/batches/{id}/export-837: regenerate X12 837 files
  for a list of claim_ids into a ZIP using HCPF file naming standards,
  with a unique interchange/group control number per export. Wire
  the clearhouse Loop 1000A (NM1*41 + PER) and per-payer receiver
  (NM1*40) blocks so the serializer no longer falls back to
  CYCLONE / RECEIVER placeholders.
- /api/parse-837 and /api/parse-835 now surface the server-side
  batch_id in both JSON and NDJSON response shapes so the frontend
  can hit batch-scoped endpoints without an extra listBatches
  round-trip.
- Filename helpers and the 837 serializer updated to match the new
  HCPF envelope; tests cover batch export, parse batch_id, and the
  serializer's control-number uniqueness guarantee.

Frontend:
- New shared components: ClaimCard, ClaimCard837, DominantKpiCard,
  EditorialNote, ExportBar, TickerTape, and a charts/ set
  (BarChart, HBarChart, SegmentedBar, AgingBars).
- New useBatchExport hook driving ExportBar's download flow against
  the new endpoint.
- ClaimDrawer, Lane, and Layout migrated from raw CSS-variable
  colors to Tailwind theme tokens (bg-card, text-foreground,
  border/60, etc.) for consistency with the rest of the instrument
  chrome; the active tab indicator gains a subtle accent glow.
- Upload, Inbox, Batches, BatchDiff, Reconciliation, and Acks pages
  reworked to compose the new shared components and consume the new
  batch-scoped API surface (notably ExportBar wired into Batches).

Tooling / Docs:
- Add audit-uiux.mjs and a docs/goodclaim.x12 sample fixture.
- Update ClaimDrawer testids and add coverage for the new
  components and the useBatchExport hook.

Rolls up into the v0.2.0 release tag.

backend/tests/test_sftp_stub.py

@@ -31,13 +31,13 @@ def sftp_block(tmp_path):
 
 def test_stub_writes_preserving_remote_path(sftp_block, tmp_path):
     client = SftpClient(sftp_block)
-    remote = "/CO XIX/PROD/coxix_prod_11525703/FromHPE/11525703-837P-20260620132243505-1of1.x12"
+    remote = "/CO XIX/PROD/coxix_prod_11525703/FromHPE/tp11525703-837P-20260620132243505-1of1.x12"
     target = client.write_file(remote, b"ISA*00*...~IEA*1*1~")
     assert target.exists()
     assert target.read_bytes() == b"ISA*00*...~IEA*1*1~"
     # Confirm the full nested MFT path is preserved under staging
     rel = target.relative_to(sftp_block.staging_dir)
-    assert str(rel) == "CO XIX/PROD/coxix_prod_11525703/FromHPE/11525703-837P-20260620132243505-1of1.x12"
+    assert str(rel) == "CO XIX/PROD/coxix_prod_11525703/FromHPE/tp11525703-837P-20260620132243505-1of1.x12"
 
 
 def test_stub_creates_parent_dirs(sftp_block):