ui/phase-19: legacy parser learns Your Groups / Your Fleets / Incoming Groups

The parity rule from ui/PLAN.md says every UI phase that decodes a
new Report field must extend the legacy converter in lockstep.
Phase 19 brings ship groups (LocalGroup / OtherGroup /
UnidentifiedGroup / IncomingGroup) and LocalFleet onto the wire-
compatible UI surface; this commit teaches
tools/local-dev/legacy-report to populate the three sections that
exist in the legacy text format:

  - "Your Groups" → []LocalGroup. Cargo type, load, fleet name,
    state, on-planet vs hyperspace position (origin / range) all
    decoded; LocalGroup.ID is synthesised deterministically from
    the per-report group index so re-running the converter
    produces byte-identical JSON. Speed is left zero — the legacy
    table doesn't expose it.
  - "Your Fleets" → []LocalFleet. Origin / range / state mirror
    the row layout used by Killer / Tancordia variants; gplus's
    state-less rows still resolve.
  - "Incoming Groups" → []IncomingGroup. Origin / destination
    names — and `#NN` by-id references — resolve against the
    parsed planet tables. Because the section can land before
    "Your Planets" in some engines, group / fleet / incoming rows
    are buffered and resolved in `parser.finish` after every
    planet is known.

Battles, OtherGroup (only ever in battle rosters), and
UnidentifiedGroup stay out of scope — README.md spells out what
remains not-derivable.

Adds Killer031–033 / TSERCON_Z032–033 / Tancordia036–039 fixtures
to the dg directory and exercises three of them through new
TestParseDg{Killer031,Tancordia037,KNNTS041} smoke tests, plus
inline tests for each new section parser. Drops the stale
KNNTS039.json artefact left over from Phase 18 development.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tools/local-dev/legacy-report/README.md

@@ -60,22 +60,47 @@ already decodes from server responses
 | `UninhabitedPlanet[]` | `Uninhabited Planets`                |
 | `UnidentifiedPlanet[]`| `Unidentified Planets`               |
 | `LocalShipClass[]`    | `Your Ship Types`                    |
+| `LocalGroup[]`        | `Your Groups` (Phase 19)             |
+| `LocalFleet[]`        | `Your Fleets` (Phase 19)             |
+| `IncomingGroup[]`     | `Incoming Groups` (Phase 19)         |
 
 Players whose name in the legacy file ends with `_RIP` are emitted with
 the suffix stripped and `Extinct: true`.
 
+`LocalGroup.ID` is synthesised deterministically from the per-report
+group index via `uuid.NewSHA1`, so re-running the converter on the same
+input file yields byte-identical JSON.
+`LocalGroup.Speed` is left at zero — the legacy "Your Groups" table does
+not expose ship speed; the UI can derive it from `pkg/calc.Speed` if
+ever required.
+Origin / Range names that don't resolve against the parsed planet
+tables (foreign-only knowledge the local player lacks) cause the entire
+group / fleet / incoming row to be dropped — preferable to fabricating
+a destination.
+
 ## Skipped sections (today)
 
-These exist in legacy reports but have no UI decoder yet, so the
-parser ignores them. Each becomes in-scope as soon as its UI phase
-lands (see "Adding a new field" below).
+These exist in legacy reports but either have no UI decoder yet or
+cannot be derived from the legacy text format at all. Each becomes
+in-scope as soon as its UI phase lands (see "Adding a new field"
+below).
 
 - Foreign / other ship types (`<Race> Ship Types`)
 - Sciences, both local (`Your Sciences`) and foreign (`<Race> Sciences`)
-- Battles (`Battle at (#N) Name`, `Battle Protocol`)
+- Battles (`Battle at (#N) Name`, `Battle Protocol`) — battle rosters
+  inside these blocks carry minimal columns (no origin / range /
+  destination) and are intentionally skipped: parsing them would
+  produce mostly-empty `OtherGroup` records that drift away from the
+  typed contract.
 - Bombings (`Bombings`)
-- Approaching / foreign groups (`Approaching Groups`, `<Race> Groups`)
 - Ships in production (`Ships In Production`)
+- `OtherGroup[]` — no top-level legacy section. Foreign groups appear
+  only inside battle rosters (see above), with stripped columns; the
+  synthetic JSON emits `otherGroup: []`.
+- `UnidentifiedGroup[]` — no legacy section at all; synthetic JSON
+  emits `unidentifiedGroup: []`.
+- `OtherShipClass[]` — present in legacy as `<Race> Ship Types`, but
+  no UI decoder yet; synthetic JSON emits `otherShipClass: []`.
 - Cargo routes — no dedicated section in the legacy text format; the
   synthetic JSON emits `route: []`. The UI's overlay path
   (`applyOrderOverlay`) supports running on top of an empty `routes`.
@@ -114,8 +139,20 @@ go test ./tools/local-dev/legacy-report/...
 ```
 
 Inline fixtures exercise the per-section row parsers; smoke tests
-parse the real `dg/KNNTS039.REP` and `gplus/40.REP` and assert
-top-level counts (number of planets, players, extinct races, ship
-classes). Field-level fidelity is the inline tests' responsibility;
-the smoke tests catch regressions where a refactor of the section
-classifier silently drops a whole table.
+parse the real fixtures under `tools/local-dev/reports/dg/` and
+`tools/local-dev/reports/gplus/` and assert top-level counts. The
+current smoke set spans:
+
+- **dg/KNNTS039–041** — KnightErrants saga; `041` is the only one
+  with `Incoming Groups`, exercising deferred name resolution.
+- **dg/Killer031** — Killer engine variant with two `Your Fleets`
+  entries (`Fl1`, `F2`).
+- **dg/Tancordia037** — the richest fixture: 311 local groups in
+  30 fleets, two incoming groups, "Incoming Groups" landing before
+  "Your Planets".
+- **gplus/40.REP** — gplus variant; tabs in headers, pseudo-cyrillic
+  ship class names, single fleet, ten incoming groups.
+
+Field-level fidelity is the inline tests' responsibility; the smoke
+tests catch regressions where a refactor of the section classifier
+silently drops a whole table.