Diod v0.1.0.28 — Mining sites and saved earthworks

Keep your island and build into it. This update adds working mining sites and
surface Cut, Fill and Level modes to the existing game.

HOW TO START
Equip a shovel or pickaxe and press G. Fill spends carried soil clods; Level
raises low ground with soil and cuts high soil. Use a pickaxe for exposed rock.
The Stone and Mining book teaches the Mining site plan, including in existing
journals. Place a plan on a hillside for a tunnel or level ground for a shaft.
Deliver 4 logs, 8 split timber, 12 cordage and 8 wooden pegs, then build its stages
with a hammer and cutting tool. Choose Mine with G once construction is complete.
Shovels remove soil; pickaxes remove local bedrock/ore. Collect loose spoil with E.
Hold V by the shaft ladder and use W/S to climb. Climbing up exits across the rim.

YOUR EXISTING SAVE
No New Game is needed. Existing terrain baselines, possessions, buildings, horses,
journal, surface digging and progress carry forward. Mines, material drops and
underground positions are saved through the same transaction system. On the first
upgrade write, a complete before-groundwork backup is created in the active run.
Do not downgrade the upgraded save; retain the backup for manual recovery.
Close Diod before replacing the whole application/folder. Windows/Linux downloads
now include a native voxel library: keep every included file beside the game.

LIMITS
Early timber workings reach 32 m from their anchor and 12 m below the entrance.
Shafts stay within 2.5 m of their ladder; digging stops above water. Foundations
and mine roofs are protected from surface earthworks. No flooding, structural
collapse, underground settlement-worker mining or unlimited tunnels are claimed.
The underground material and timber visuals are an initial implementation, using
the existing terrain shader. Finite tool strokes are balanced game quantities.

VALIDATION
Targeted save migration/recovery, explicit collection, tool/soil/rock rules, paid
construction, terrain joins, surface work and island-coast regression checks.
Native Apple M4 Metal Low tests include normal underground walking/tool use,
streaming away and returning, saved underground positions, G/Escape and ladder
escape. Tests use finite granted fixtures, not a new zero-resource survival run.
Final platform-specific export/signing checks are recorded beside this release.
Windows signing, native Windows/Linux GPU playtesting and laptop FPS measurements
remain unavailable. Existing known Metal LOD-bias warning persists.