Silo contents at a glance (t38); drill aimed past its reach stays calm (t41)

Silos show a wide fill window in the material's colour in both looks,
and the cursor label names the contents anywhere over the outline.
Aiming the drill beyond its reach keeps normal colours, marks where the
pulse stops, and drops the red circle and the out-of-reach toast.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/PROJECT_MAP.md

@@ -287,7 +287,7 @@ Bars and other loose objects (ents), and the bag: adding, taking, costs and refu
 Tool helpers: reach, brushes, and plain digging.
 - functions: inReach, forBrush, drillReach, inDrillReach, toolDig
 
-### src/sim/drill.js (161 lines)
+### src/sim/drill.js (160 lines)
 The resonance drill: tuned pulses that shatter one material.
 - functions: drillOrigin, pulseRay, builtCell, toolPulse, crumbleAround, crumbly, shatterCell, pulseTick
 - variables: PULSE_W, PULSE_EVERY, PULSE_SPEED, PULSE_K, drillPulses, lastPulseTick, drillWidth, THIN_BONUS, CRUMBLE_MAX, THIN_BONUS_OFF
@@ -366,9 +366,9 @@ Scale colour without changing the smooth-look class.
 - functions: fogColor, diagonalTubeJoins, diagonalTubeShape, diagonalTubeBlock, drawWorld
 - variables: TUBE_CLASS, diagonalJoins, diagonalAcross, diagonalAlong, diagonalCap
 
-### src/render/machines.js (242 lines)
+### src/render/machines.js (256 lines)
 Machine overlays: fans, engines, silo and the rest, drawn on top of the world.
-- functions: cellRect, drawHazardRims, drawMachines, drawProcBlocks, drawSilo, drawSiloPixel, drawRackBlocks
+- functions: cellRect, drawHazardRims, drawMachines, drawProcBlocks, drawSilo, drawSiloPixel, drawSiloWindow, drawRackBlocks
 
 ### src/render/overlays.js (229 lines)
 Other overlays: floating text, rain and snow, flow arrows, filter tags, molds, the bot, particles.
@@ -457,7 +457,7 @@ Selection panels: current tool card and bag materials.
 - functions: renderSelCard, renderBag
 - variables: lastBagKey
 
-### src/ui/info.js (189 lines)
+### src/ui/info.js (195 lines)
 Discovery cards, hover info (I) and the cursor label.
 - functions: showCard, howText, discoveryCard, reactionsOf, hoverInfo, renderInfo, drawCursorLabel, pipeContentsText
 
@@ -476,11 +476,11 @@ Gamepad input.
 - functions: padPressed, pollPad
 - variables: PAD
 
-### src/ui/previews.js (237 lines)
+### src/ui/previews.js (234 lines)
 Cursor previews: shared grid helpers, air streaks and tool preview dispatch.
 - functions: blockRectPx, drawGrid, previewColor, drawAirStreaks, drawReachCircle, drawPreviews, previewBlock
 
-### src/ui/preview-drill.js (104 lines)
+### src/ui/preview-drill.js (107 lines)
 Drill previews: shaken rock cracks, pulse wavefronts and aiming fan. Rock the drill has shaken but not yet broken shows cracks, more and finer as it nears breaking. Each crack is a contour line of a noise field (marching squares, cell by cell), so the lines run on unbroken from one cell to the next and look like real fractures, not a pattern.
 - functions: crackSeg, drawCracks, pulseRGB, fanPoints, drawDrillPulses, drawDrillAim
 - variables: CRACK_N, CRACK_LV
@@ -527,6 +527,7 @@ The frame loop and boot.
 - `test/t_physics.js`: Sand and other powders, molten metal and gases: heaps, sorting, sinking, setting, rising and fading. Water has its own suite (t_water.js). Tall worlds keep geothermal heat out of the way.
 - `test/t_pipes.js`: Pipes, pumps and outlets move liquids; the Grinder grinds waste rock for trace ore.
 - `test/t_racks.js`: Rack intake, FIFO storage, gate, removal and saved-state validation.
+- `test/t_silo_contents.js`: Stored snow keeps its identity and remains in the world's water budget.
 - `test/t_sim_optimizations.js`: Optimized paths must match the full roof scan and the original heat loop exactly.
 - `test/t_slope_belt_art.js`: Drawing geometry against real parts, without changing transport.
 - `test/t_slope_belts.js`: Sloped belts: transport, joins, sorting, persistence and the actual drag controls.