docs: capture deferred work in README Roadmap

Consolidates everything that was floating in chat-only "parking
lot" status into the README's Roadmap (Future) section:

  High-impact (unblocks product features):
    - Waveform body codec reverse-engineering
    - In-app waveform viewer accuracy (depends on codec)
    - Terra-view integration
    - Vibration summary reports

  BW ASCII report parser enhancements:
    - Histogram-specific structural fields
    - Histogram interval bin-table parsing
    - ">100 Hz" value parsing

  Ingestion gaps:
    - MLG forwarding (watcher + SFM endpoint)
    - 0C-record raw bytes persistence in sidecar

  Operational:
    - series3-watcher file archive manager
    - Existing operational items (compliance encoder, modem manager,
      Call Home dial_string write, histogram mode 5A stream)

  Test coverage + lower-priority cleanups.

CLAUDE.md "What's next" section now points to the README as the
canonical deferred-work list, and keeps its own low-level technical
status log for byte-layout details that don't belong in the
roadmap.

CLAUDE.md

@@ -1353,6 +1353,8 @@ body) because writing a dial string may require DLE escaping for embedded contro
 
 ## What's next
 
+**See [README.md → Roadmap (Future)](README.md#roadmap-future) for the canonical deferred-work list.** This section is kept as a status log of in-progress / recently-shipped technical details (encoding schemes, byte layouts, etc.) that are too low-level for the README's roadmap.
+
 - **Database** — SQLite store for events + monitor log entries; dedup by key; queryable
 - **Histograms** — decode histogram-mode A5 data (noise floor tracking)
 - **Blastware-compatible file output** — `write_blastware_file()` and `write_mlg()` implemented. `blastware_filename()` generates correct Blastware filenames (AB0 for direct, AB0W/AB0H for ACH). **Confirmed BYTE-PERFECT against BW reference (v0.14.3, 2026-05-05):** when fed the BW 5-1-26 3-sec capture's A5 frames, the SFM-built file matches BW's saved `M529LKIQ.G10` byte-for-byte (8708 bytes, 0 differences).  Live SFM downloads of event 0 (3-sec) and event 1 (3-sec continuation) both open cleanly in Blastware with full Event Reports, frequency analysis, and waveform plots.  Body assembly is just contiguous concatenation of frame contributions in stream order (probe → meta@0x1002 → meta@0x1004 → samples → TERM); no stripping, no overlay, no special handling.  Histogram+Continuous mode deferred (5A stream for those events embeds histogram interval records that may need different handling — untested under v0.14.x). Extension mapping: extensions encode timestamp (AB0T for ACH, AB0 for direct), NOT recording mode. Filename format: `<prefix_letter><serial3><4-char-base36-stem><ext>`