Served with isolation headers; start-screen capability notices; tests on the real GPU (t88 phase 1)

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

docs/PROJECT_MAP.md

@@ -19,8 +19,9 @@ src/render/           drawing: the pixel look (CPU) and the smooth look (WebGL2)
 src/ui/               the browser shell: input, HUD, build menu, notebook, settings, saves,
                       audio, the frame loop
 test/                 headless suites (t_*.js) and their harness; browser tests (play.py,
-                      t_smooth.py, t_dev_console.py); run_all.py
+                      t_smooth.py, t_dev_console.py, t_caps.py, firefox_smoke.py); run_all.py
 tools/                serve.py (build, serve, rebuild on change), server.py (isolated HTTP), shot.py (screenshots),
+                      browser.py (shared launch/GPU choice), caps.py (capability report),
                       where.py, map.py, perf.py, playthrough.py, use_venv.py (switches browser
                       scripts to .venv), scenes/ (screenshot setups), experiments/
                       (measurements and reports)
@@ -441,10 +442,10 @@ Game shell (src/ui/): browser only. This file: settings, the GAME state object,
 - functions: loadSettings, saveSettings, el, esc, rgbOf, fmtT, toast, setStatus
 - variables: SET_DEFAULT, SET, TOOLS, ICONS, BAG_ORDER, GAME, keys, hudDirty, $
 
-### src/ui/title.js (46 lines)
-The title screen art.
-- functions: buildTitleCells, drawTitle
-- variables: FONT5, TITLE
+### src/ui/title.js (74 lines)
+Startup capabilities and title art.
+- functions: checkCapabilities, renderCapabilityNotice, canStartGame, buildTitleCells, drawTitle
+- variables: REQUIRE_GPU_AND_THREADS, CAPS, CAPS_CHECK, FONT5, TITLE
 
 ### src/ui/saves.js (224 lines)
 Saves in IndexedDB, world files (export / import) and the blueprint library.
@@ -456,7 +457,7 @@ Shared player state; the world save remains a complete standalone fallback.
 - functions: careerState, validCareer, applyCareerState, loadCareer, claimName, openNewClaim, travel, renderClaimsTab
 - variables: career, claimBusy
 
-### src/ui/session.js (158 lines)
+### src/ui/session.js (160 lines)
 Starting, loading and quitting a game; modal dialogs; the pause menu.
 - functions: showLoading, enterGame, setupNewWorld, startNewWorld, startFromSave, loadSavedWorld, quitToTitle, refreshContinue, anyModal, openModal, closeModal, closeAllModals, topModal, dialog, openPause, renderWorlds
 
@@ -564,6 +565,7 @@ The frame loop and boot.
 
 ## Tests and tools
 
+- `test/firefox_smoke.py`: An isolated Firefox title screen and three seconds of a new pixel world.
 - `test/furnace_play.js`: Fires a starter furnace design repeatedly the way a player would, without cleaning it out between firings, to see whether it clogs. Usage: node test/furnace_play.js [design] [ore] [coal] [firings] [roll] [mode] mode: 'mix' (even ore/coal mix blown in), 'layers' (ore first, coal on top), 'vent' (blown in from above through the vent)
 - `test/harness.js`: Loads the simulation (the src/sim/ files listed in src/manifest.json, joined in order into one script, the same way build.py joins them) so scenarios can drive it headlessly in Node. Errors point at the real file and line (sim/pipes.js:42), not at the joined script.
 - `test/play.py`: Play-test in a real browser: mouse, keyboard and a mocked gamepad drive the game; save and continue. Screenshots go to shots/play/ (or the folder given as the first argument). Pixel look unless the second argument is 'smooth'.
@@ -571,6 +573,7 @@ The frame loop and boot.
 - `test/t_bar_stacking.js`: Resting bars snap into pairs of grains and tip off narrow supports.
 - `test/t_basics.js`: Basics: drilling to rubble, the vacuum and blowing, walls, the ingot mold and bars, belts, blueprints, save/load.
 - `test/t_build.js`: Building: undo (Ctrl+Z), cut, replace a machine with Ctrl, pasting ghosts, and the fan heat warning.
+- `test/t_caps.py`: Capability detection, title warnings and the future startup gate.
 - `test/t_conveyors.js`: Screw conveyors that never carry liquid (it flows through), screw and belt throughput, filters.
 - `test/t_corner_seal.js`: Corner-touching square walls seal loose grains without changing free piles or worldgen.
 - `test/t_cursor.js`: Ore identification, cached connected veins, ping timing, settings and label lifetime.
@@ -601,6 +604,8 @@ The frame loop and boot.
 - `test/t_water.js`: Water conservation, settling, ledge pouring, boundaries, pipes and phase changes. Tall worlds keep geothermal heat out of the ponds.
 - `test/t_weather.js`: Weather: no more springs; steam rises into clouds and rains back; showers; snow when it is freezing.
 - `test/t_world.js`: Trees from acorns, charcoal, brick, density, water/lava/snow/ice, full-bag refunds, drill reach, ballistic blowing, snowy mountains.
+- `tools/browser.py`: Shared isolated HTTP sessions; callers attach hooks before navigating to url.
+- `tools/caps.py`: Print isolation, WebGPU adapter info and GL renderer for installed browsers.
 - `tools/map.py`: Regenerate the file and symbol index at the end of docs/PROJECT_MAP.md.
 - `tools/perf-measure.js`: Temporary wrappers live only in the profiling page, never in the simulation bundle.
 - `tools/perf-scenes.js`: Seeded worlds, no storage round-trip (saves quantize heat and land flying grains).