fix(idf): decode from in-memory bytes during ingest

Bug shipped in v0.21.0: save_imported_idf called read_idf_file()
with `source_path` (a bare filename like "UM12947_….IDFW") BEFORE
writing the binary to disk.  The codec did Path(path).read_bytes()
which resolved relative to /app and hit FileNotFoundError.  The
error was caught + logged as a warning, and ingest fell back to
.txt-only — events still landed in the DB but lost the bw_report
block + .h5 waveform that the codec was supposed to produce.

Observed during a full re-forward from thor-watcher on 2026-05-29:
every Thor event logged "binary codec failed for X: [Errno 2] No
such file or directory" and got binary_decoded=False.

Fix:
- read_idf_file() gains a `data: Optional[bytes]` kwarg.  When
  supplied, skips the disk read and decodes the provided bytes
  directly.  `path` stays required (used for filename in error
  messages + .IDFH vs .IDFW suffix detection); only the read is
  conditional.  Backward compatible — existing positional callers
  (CLI scripts, tests) continue to work unchanged.
- save_imported_idf passes `data=idf_bytes` since the bytes are
  already in memory from the multipart upload.  Filesystem write
  still happens at step 5 of the existing flow; codec just no
  longer depends on it.

Verified end-to-end against UM11719_20231219162723.IDFW from the
example-data corpus: ingest endpoint returns inserted=1, log line
shows binary_decoded=True + h5=...IDFW.h5, no warnings.

Re-forward existing Thor events from thor-watcher after deploy to
backfill the bw_report block — UPSERT preserves review state.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

micromate/idf_file.py

@@ -326,7 +326,11 @@ class IdfReadResult:
     intervals:       Optional[list] = None  # list[IdfhInterval] for IDFH; None for IDFW
 
 
-def read_idf_file(path: Union[str, Path]) -> IdfReadResult:
+def read_idf_file(
+    path: Union[str, Path],
+    *,
+    data: Optional[bytes] = None,
+) -> IdfReadResult:
     """Parse a Thor ``.IDFW`` binary into an ``IdfEvent`` + decoded samples.
 
     Currently implements signature-A waveforms only.  Signature-B
@@ -337,9 +341,14 @@ def read_idf_file(path: Union[str, Path]) -> IdfReadResult:
     Returns an :class:`IdfReadResult`.  The caller converts int sample
     counts to physical units via :func:`geo_count_to_ips` /
     :func:`mic_count_to_psi`.
+
+    ``path`` is used for filename in error messages and ``.IDFH`` vs
+    ``.IDFW`` suffix detection.  When ``data`` is supplied the disk
+    read is skipped — useful for ingest paths that already have the
+    bytes in memory and where the file may not exist on disk yet.
     """
     p = Path(path)
-    buf = p.read_bytes()
+    buf = data if data is not None else p.read_bytes()
 
     if len(buf) < 16 or buf[6:16] != _INSTANTEL_TAG + b"\x00":
         raise ValueError(f"{p.name}: not an IDF file (missing Instantel magic)")