Add a worked create-mode probe example

[wormeyman]

The repo had no example of a probe mod, only integration tests. This is a real one that earned its place: it settled FactorioTools issue #81 and caught a breaking runtime API change nobody had noticed.

What it does

Places pumpjacks in all four rotations and reads PipeConnection.target_position - the tile the connecting pipe actually occupies - from the running game.

That matters because a --dump-data capture answers a different question. The prototype's output_fluid_box.pipe_connections gives the connection point inside the entity, and the pipe sits one tile further out in the facing direction. Deriving one from the other means trusting a convention rather than reading an answer.

What it measured

Against real 2.0.77 and 2.1.14 installs, offsets relative to the pumpjack center:

Facing	2.0.77	2.1.14
north	(1,-2)	(1,-2)
east	(2,-1)	(2,1)
south	(-1,2)	(-1,2)
west	(-2,1)	(-2,-1)

2.0 gave four rotations only two distinct corners: east reused north's, west reused south's. 2.1 gives each its own. FFF #442 is the release that did it, alongside use_mirroring and migrate_horizontal_mirroring on the same prototype.

Running both versions is the part worth copying. The 2.0.77 column reproduces what FactorioTools already has hardcoded, so the probe is shown to give the known-good answer before being believed about the new one. A probe that only runs against the version you care about cannot tell you that.

The 2.1.14 column was also produced twice, on Windows and macOS builds of 87180, and matches - consistent with --dump-data being byte-identical across those platforms for a given build.

Two traps it documents

Factorio 2.1 deleted LuaEntity.fluidbox and the entire LuaFluidBox class, flattening it onto LuaEntity as get_fluid_box_*. entity.prototype.fluidbox_prototypes[i].pipe_connections still works in both, so prototype-level reads need no branching.

Feature detection needs a pcall. Reading an unknown key on LuaEntity raises in 2.0 rather than returning nil, so if entity.get_fluid_box_pipe_connections then throws on the older version instead of being false.

Verification

Ran end to end through the CLI on macOS:

factorio-oracle run --probe examples/pumpjack-terminals/probe.json --work-dir /tmp/pj

reports "ok": true, writes oracle-dump.json, and loads all six bundled mods. Output matches the Windows run exactly.

cargo fmt, cargo clippy -D warnings and cargo test --all-targets all pass. Docs and example data only - no library code changes.