feat(messages): parse GOAT work areas and zone metadata

[monsivar]

Stacked draft — not ready for merge. Depends on #1782, transitively on #1567.

The diff against dev is currently cumulative because the dependency branches live in the contributor fork. It will be reduced as the preceding PRs land.

Summary

This PR implements the read-only work-area layer from step 2 of #1785 for the GOAT O1200 LiDAR Pro.

It combines:

• onArI work-area geometry;
• getAreaSet type="ar" area IDs and user-visible names;
• deterministic registration of each area from its local coordinates into the static onMI map coordinate frame.

The output uses the same shared mower representation as #1567 and #1782:

MowerMapTraceGroup → MowerMapTraceSegment → points

The original firmware geometry record remains preserved as raw.

onArI geometry

The observed complete onArI type=0 representation is handled as a chunked snapshot:

• strict canonical Base64 per chunk;
• chunks grouped and validated by snapshot identity;
• serial defines the expected chunk count;
• indexes must form the complete 0..serial-1 sequence;
• chunks are concatenated before trimmed LZMA-Alone decoding;
• decoded length must match the evidenced infoSize.

The persistent work-area geometry is carried in layer "1".

Each observed area record contains an area ID, a local start coordinate and the same eight-direction RLE path representation used by the static map. The observed O1200 step size remains 50 coordinate units and is not generalized to all mower models.

getAreaSet metadata

getAreaSet type="ar" supplies the persistent area metadata used to associate geometry with user-visible names.

The observed rows contain:

• map ID;
• area ID;
• user-visible area name;
• additional opaque fields which are not assigned undocumented semantics.

Empty names are valid.

The response envelope aid is not interpreted as a work-area ID.

AreaSet framing

Controlled O1200 captures showed that the AreaSet envelope infoSize is not the decompressed payload length.

The parser therefore:

• still validates the envelope infoSize as positive opaque metadata;
• uses the decompressed-size value from the trimmed LZMA-Alone payload header;
• verifies the actual decoded byte length against that internal size;
• applies a 1 MiB decompressed-size safety limit.

The fixture includes a real observed mismatch where envelope infoSize=286 while the internal/decompressed size is 140.

This behavior is intentionally limited to AreaSet and is not generalized to onMI or onArI.

Area registration

Work-area polygons are not stored at their final position in the main-map coordinate frame.

Registration therefore does not use model-specific fixed offsets.

For each work area the implementation:

1. expands the RLE direction sequence;
2. finds the longest shared contiguous direction sequence between the local area contour and the static onMI boundary;
3. derives the corresponding translation from the matched point indexes;
4. translates the complete area geometry;
5. validates the matched run exactly after translation;
6. rejects ambiguous best matches when they imply different translations.

No scale or rotation is introduced by this registration step.

Public model

The resulting snapshot is exposed as:

• MowerWorkArea
  • name
  • geometry
• MowerWorkAreasEvent
  • mid
  • areas
  • step_size

geometry.group_id preserves the work-area ID while its points are registered into the static-map coordinate frame.

Safety

Parsing and registration are fail-closed.

Malformed or incomplete chunk sets, invalid Base64/LZMA framing, invalid RLE data, incompatible map IDs, excessive sizes, missing metadata, or ambiguous registration do not produce a misleading work-area snapshot.

Scope

This PR intentionally does not implement:

• SVG rendering;
• the shared Map capability;
• acquisition/session lifecycle;
• hardware wiring;
• mower or dock position;
• live-position coordinate transforms;
• onMapTrack;
• map editing or write commands.

Dependencies and follow-up

• feat(messages): add OnMapTrace for mower firmware (LZMA-wrapped variant) #1567 — shared mower geometry representation.
• feat(messages): parse mower onMI static map geometry #1782 — static onMI main-map geometry.
• This PR — onArI + getAreaSet work areas and registration.
• Follow-up — integration into the existing Map capability and Rust SVG renderer.
• Later — acquisition/session lifecycle and hardware wiring.

This also supersedes the map-zone parsing direction of #1774. That PR should remain untouched until this draft has been reviewed.

Validation

The rebased implementation was validated locally with the relevant onMI, work-area and message-routing tests:

67 passed

[codecov]

Codecov Report

❌ Patch coverage is 90.52288% with 58 lines in your changes missing coverage. Please review.
✅ Project coverage is 95.75%. Comparing base (7fb6b38) to head (512af5e).
⚠️ Report is 58 commits behind head on dev.

Files with missing lines	Patch %	Lines
deebot_client/messages/json/map/work_areas.py	82.62%	28 Missing and 25 partials ⚠️
deebot_client/messages/json/map/__init__.py	97.63%	1 Missing and 2 partials ⚠️
deebot_client/messages/json/map/o1200.py	96.96%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              dev    #1788      +/-   ##
==========================================
+ Coverage   95.02%   95.75%   +0.72%     
==========================================
  Files         159      164       +5     
  Lines        6234     7000     +766     
  Branches      353      472     +119     
==========================================
+ Hits         5924     6703     +779     
+ Misses        248      202      -46     
- Partials       62       95      +33     

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[codspeed]

Merging this PR will not alter performance

✅ 226 untouched benchmarks

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_{Comparing monsivar:feature/goat-map-work-areas (512af5e) with dev (5453eba)}