[Frontend] TdDialog/useVisualViewport residuals: pinch-zoom scale, prefix validation, ungated geometric E2E (PR #1864 review)

[Chris0Jeky]

Residuals from the PR #1864 review (TdDialog visual-viewport binding, #1821):

1. Pinch-zoom is conflated with keyboard contraction — useVisualViewport never consults visualViewport.scale, so zooming resizes/repositions every dialog on the same path as a keyboard contraction. Decide: ignore scale>1 events, or accept the behavior deliberately.
2. prefix option is documented "must start with --" but not validated — a bare prefix produces style keys Vue silently drops. A DEV-only warn would catch it.
3. The geometric E2E is not gated by required CI — E2E Smoke / Cross-Browser report skipping on the PR, so mobile-responsive.spec.ts geometry runs only locally. Consider adding the mobile-responsive spec to a gated lane, or record that it is local-evidence-only.
4. At the <=640px breakpoint the 100vh/100dvh pairs on .td-dialog are dead (percentages win everywhere) — annotated in-PR; delete when next touched.

Source: PR #1864 review non-blocking items 2-4 + tidy-up. The review's item 1 (fallback-chain hole) was fixed in-PR.

[Chris0Jeky]

[Codex lane claim]\n\nScope: TD-1867-prefix-warning only. I will add the documented DEV-only warning when useVisualViewport receives a prefix that does not start with --, using the existing frontend warning helper. I will add focused valid/invalid prefix specs.\n\nOwned paths: frontend/taskdeck-web/src/composables/useVisualViewport.ts and frontend/taskdeck-web/src/tests/composables/useVisualViewport.spec.ts only. No pinch-zoom policy, CSS cleanup, or CI-gating changes.\n\nAcceptance: valid prefixes do not warn; invalid/bare prefixes warn once per composable invocation in development; production behavior and emitted style values remain unchanged.\n\nBase: origin/main at execution time.\n\nStatus: active.

[Chris0Jeky]

[Codex lane release]\n\nPR: #2648 (https://github.com/Chris0Jeky/Taskdeck/pull/2648)\nexact head: 2fb4d09\nresult: ready for review; test-backed TD-1867-prefix-warning slice.\n\nChanged the useVisualViewport composable to emit one development-only warning for an empty, bare, or marker-only prefix through the existing logWarn helper. Added valid/invalid prefix coverage. No pinch-zoom, CSS, or CI policy changes.\n\nVerification: focused viewport spec 10/10;
pm run typecheck; strict two-file ESLint;
pm run build; and git diff HEAD^ HEAD --check all passed.
pm ci emitted the repository's existing two moderate audit advisories and engine/deprecation warnings; package files were unchanged.\n\nThe parent issue remains open for its separate zoom-policy, dead-CSS, and geometry-CI rows.

[Chris0Jeky]

Bounded slice: TD-1867-dead-css

PR #2657 removes only the four mobile TdDialog viewport-height declarations already proven unreachable by the later percentage pair. The effective max-height: 100%/height: 100% rules and the upstream VisualViewport/dvh fallback chain are unchanged.

• exact head: fb2534e28
• focused proof: TdDialog.spec.ts 16 passed, 0 failed, 0 skipped
• typecheck, scoped ESLint, production build, and git diff --check passed
• build reported only the existing ineffective dynamic-import warning
• the prefix-warning implementation remains separately scoped to PR [Frontend] Warn on invalid visual viewport prefixes #2648; pinch-zoom and geometry-CI decisions remain open

Refs #1867