Epic: Mobile and responsive shell

[mparrett]

Supersedes the exploratory stack #111–#127 and the integration preview #116.

TL;DR - 🚀 just play it.

Reviewing on desktop? 🕹️ ?mode=dev forces the touch shell (D-pad + action UI) without a phone · ?mode=debug adds turn/perf diagnostics.

What this tracks

The mobile and responsive-shell work is going up as 11 focused PRs, each scoped to a single concern and stacked linearly. The assembled set reproduces the tree already on #116: the re-slicing changes the commit shape, not the code, so each concern reviews and merges on its own.

Slices

All 11 carry the browser-mobile label — open the filtered PR list to review them together.

Shared-render (off main):

• build-info (build-info: build-info.json generator shared by make and CI #129): build-info.json generator shared by make wasm and CI · base main
• bench (bench: native engine benchmark + shared xsofy.perf core #130): native engine benchmark + shared xsofy.perf core
• render (render: responsive camera + narrow-terminal rendering #131): dead-zone camera + viewport follow + narrow-terminal layout collapse
• topbar (topbar: narrow-width in-grid HP/status bar #132): narrow-width in-grid HP/status bar when the sidebar folds
• screens/reflow (screens/reflow: reflow title and death screens on resize #133): reflow title and death screens on resize / font-change

Mobile shell (stacks on topbar):

let-go dependency (shell lane only). The client shell binds let-go's host-frame mount, which let-go #378 renames #terminal → #app (and ships visible). So #135 bumps .let-go-version from v1.11.1 to cf195a6 (the #377 + #378 squash) and binds #app; #136–139 inherit the pin. #134 and the shared-render lane stay on v1.11.1 and are unaffected. The pin is a commit ahead of the next release, not a tag — a tagged release carrying #377+#378 can replace it once one is cut.

• bridge (bridge: ui-bridge HUD channels + startup/stats wiring #134): ui-bridge HUD channels + startup/stats wiring
• shell (feat(mobile): blank client-shell scaffold (structure + hooks) #135): touch shell (client-owned host, D-pad/action UI, dark mode) + dev-gating (?mode=) + OPTIONS panel
• fit (fit: debounced re-fit + letterbox the grid #136): debounced resize / orientation re-fit + letterbox the grid
• landscape (feat(mobile): touch shell redesign — portrait + landscape #137): horizontal split layout for phone landscape
• screens/nudge-guard (screens/nudge-guard: ignore the shell's resize nudge on modal reads #138): ignore the shell's resize nudge on modal and prompt reads

Tail:

• title-moat (title-moat: keep decorative runes off the title text #139): keep decorative runes off the title, prompt, and seed text

Integration reference

integ/mobile-stack is a single squashed commit of the whole set: the diff to review the change as a whole without merging. Its tree matches #116's tip, except it drops #116's preview-only review doc.

Design reference

A visual walkthrough of the design — camera, layout collapse, touch shell, phone landscape, resize handling — with trigger conditions and the layout shape at each size: rendered HTML.

Landing order and independence

Linear by default, but the graph has slack:

• Shared-render: build-info, bench, render, topbar, and screens/reflow are all off main. They don't depend on the mobile shell and can go in independently.
• Mobile shell: bridge, shell, fit, landscape, and screens/nudge-guard form one dependent chain on top of topbar, in that order.
• title-moat is order-free, disjoint from everything else.
• build-info must precede shell: the shell fetches build-info.json, and without the generator the browser-smoke gate fails on the missing file.

So the shared-render slices and title-moat can merge whenever; the mobile lane goes in order.

Why re-slice

The previous stack grew by exploration: churn that was added and later removed, one concern spread across several PRs, and two unrelated concerns sharing a commit. This set regroups the same final tree into one PR per concern: a touch shell that arrives in one piece, a screens fix separated into its shared-render half and its shell-specific half, and build-info pulled out so its ordering constraint is explicit. Same code, reviewable in coherent pieces.