feedback1d WO: the preference route is 0.1.0's again; equal floor keeps the official route

Review follow-up to the D5 fix. Two changes in grid.js _buildField:

- The road-over-floor preference smoothing is 0.1.0's again: its line of sight
  may cover non-blockable tiles (Bresenham footprint, diagonal-step corners
  included) only on the tile's own raw chain, and the jump stops at the first
  ancestor it cannot see so. Exact crossings (a corner touch is not a crossing)
  are used only to choose between the official and the preference pointer.
  The previous version let the preference brush the corner of off-chain floor,
  so on 战场#02's Final Assault the right-half exit route (2,10) -> (3,11)
  slipped past an operator on (2,11) while the left half was still blocked on
  (2,9). Both halves now mirror each other again ((2,10) -> (2,11) -> (4,11)).
- On an equal floor count the official pointer stays; the preference pointer
  wins only when it merely skips a collinear official waypoint (same walk).
  The old "farther waypoint" tie-break could bend an official route without
  saving any floor, e.g. a crate on (10,6) of 战场#04 brought back the L via
  (9,8) for the lower gate.

Still 140 of 154 stage routes official; data/stages.json groundPaths
regenerated (战场#02 boss right exit back to 0.1.0's, device-less helper paths
of #03 / #04 / #06 follow the same rule). New tests: 战场#02 boss exits mirror
and are blocked beside the exit; a single crate on any tile of an active stage
never leaves a gate route non-official without crossing strictly less floor.
The cross-check reference port follows both rules.

docs/DATA.md

@@ -409,7 +409,7 @@ exactly (the builder warns if a multi-fragment template ever appears).
 | `special` | `{"mire":{"intervalSec":3,"aspdPerStack":-0.05,"moveMulPerStack":-0.05,"maxStacks":10,…}}`, `{"infection":{"bb":{"damage":70,"atk":0.2,"attack_speed":20,"duration":300}}}`, `{"deepsea":{"skillId":"sktok_tidectrl_3","bb":{…}}}`, `{"smog":{"rule":"operatorsNotTargetableByEnemyRanged"}}`, `{"blower":{…}}` | special-terrain parameters |
 | `runes[]`, `globalBuffs[]` | `{"key":"map_tile_blackb_assign","bb":{…},"bbStr":{…}}` | level runes (act2 m03 reed rune has no reed tiles — leftover) |
 | `deployTiles` | `{"normal":{"melee":[[9,3],…],"rangedOnly":[[10,4],…],"changedByDevices":[…]},"bossLeft":{…},"bossRight":{…}}` | deployable tiles at match start: `melee` = LOW buildable ALL/MELEE (ranged may use them too), `rangedOnly` = high ground / active platforms; tiles under active crates/mounds excluded. `bossLeft` / `bossRight` (field coordinates, boss rows 1–5) are what a player may deploy on in a boss round's prep: board (r, c) = boss (r − 7, c) / the right half mirrored (r − 7, 20 − c) (server/match/board.js `field`, user playtest #5 item 7) |
-| `groundPaths` / `groundPathsWithDevices` | `{"12,10->9,2":[[12,10],[12,9],…,[12,3],[11,3],[10,3],[9,3],[9,2]]}` | the ground route of the sim's own `server/sim/grid.js` flow field (research 08 §3.4: 4-direction SPFA from the goal, crates cost 1000, Bresenham line-of-sight smoothing — official route lengths — kept unless the remake's road-over-floor preference route crosses fewer non-blockable floor / gate tiles — the fewest among equal-length chains, smoothing that never cuts across floor its grid route does not walk, a corner touch not counting as a crossing — e.g. 战场#01's lower gate takes the col-8 road, not the col-9 floor lane, while 战场#04's keeps the official diagonal from row 9 into row 10; DESIGN §14 corrections, test/sim/pathing-official.test.js) as the tiles an enemy crosses, over the whole map, without / with the match-start devices (crates cost 1000, platforms / mounds blocking [ASSUMED]); the battle re-reads its flow fields live |
+| `groundPaths` / `groundPathsWithDevices` | `{"12,10->9,2":[[12,10],[12,9],…,[12,3],[11,3],[10,3],[9,3],[9,2]]}` | the ground route of the sim's own `server/sim/grid.js` flow field (research 08 §3.4: 4-direction SPFA from the goal, crates cost 1000, Bresenham line-of-sight smoothing — official route lengths — kept unless the remake's (0.1.0's) road-over-floor preference route crosses strictly fewer non-blockable floor / gate tiles — the fewest among equal-length chains, smoothing that never cuts across floor its grid route does not walk; a corner touch does not count as a crossing — e.g. 战场#01's lower gate takes the col-8 road, not the col-9 floor lane, while 战场#04's keeps the official diagonal from row 9 into row 10; DESIGN §14 corrections, test/sim/pathing-official.test.js) as the tiles an enemy crosses, over the whole map, without / with the match-start devices (crates cost 1000, platforms / mounds blocking [ASSUMED]); the battle re-reads its flow fields live |
 | `options`, `config` | `{"characterLimit":8,"moveMultiplier":0.5}`, `{…configBlackBoard strings…}` | |
 
 Glyph legend (`rows`):