feat(ink-compat): extend Ink compatibility layer parity

[RtlZeroMemory]

This PR extends @rezi-ui/ink-compat toward Ink parity (G1–G7 scope).

Parity features

• Measurement APIs: measureElement() committed-layout reads + getBoundingBox(), getScrollHeight()/getScrollWidth()
• ResizeObserver implementation wired to committed layout snapshots
• Render options parity: onRender, isScreenReaderEnabled, alternateBuffer, incrementalRendering (best-effort surface)
• useStdin() raw-mode behavior: meaningful isRawModeSupported, ref-counted setRawMode() toggles, clearer unsupported errors
• Compat smoke: third-party-like patterns for spinner (interval state updates) and gradient (Transform receives flattened text)

Core plumbing

• createApp() internal callbacks for render/layout (internal_onRender, internal_onLayout)
• Widget layout snapshot accessor: WidgetRenderer.getRectByIdIndex() + committed id->rect indexing used by ink-compat measurement

Validation

• npm run build (pass)
• npm run typecheck (pass)
• npm run test (pass; 920 tests)

Known deviations / constraints

• incrementalRendering: accepted for Ink surface parity; currently best-effort/no-op in this implementation
• Alternate buffer & stdio ownership: backend stream ownership constraints (Node backend doesn’t currently accept stdio overrides)
• Some scroll/raw-mode edge behaviors may differ from Ink in unusual stream/TTY configurations

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Preserve caller-owned alternate buffer state on cleanup

When alternateBufferAlreadyActive is set, this render call starts with alternateBufferActive = true even though it did not enter the alternate buffer itself, but cleanupAlternateBuffer() still unconditionally writes the exit sequence whenever alternateBuffer is enabled. In nested/embedded use (where a parent already owns the alternate buffer), unmounting this instance will send \u001B[?1049l and tear down the parent’s buffer unexpectedly, causing terminal screen/state corruption outside this app.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

Avoid reusing IDs across accumulated Static snapshots

This assigns node.internal_id into rendered vnode props, including the <Static> path where vnodes are appended to root.staticVNodes over time, so the same host node ID is duplicated across historical static entries. Core layout indexing keeps the first rect for a given id (buildLayoutRectIndexes only sets when the id is absent), so later snapshots can no longer update that node’s measured rect; measureElement/ResizeObserver for static boxes can become stale after additional static emissions.

Useful? React with 👍 / 👎.