[tiensonqin]

Summary

Bounded MyGo Stacks now pass finite width and height through their synthetic layer wrappers instead of letting intrinsic content floors expand nested scroll viewports. Use single-cell Fr(1) grids for both the Stack and each wrapper; retain keys, placement, pointer pass-through and z-order. Content-sized Stacks and explicit child constraints keep their existing semantics.

Add optional typed Config.InputValue func(Node, *string) and InputControl func(Node, ui.Element, string) hooks for standard text editors. Value binding runs after model reconciliation and before editor construction; control binding runs after input-handler setup and before existing focus/handle/autofocus processing. Both run only during live construction, never fitting probes. Hosts can reuse their existing imperative queues and incarnation/commit acknowledgement instead of copying the renderer or adding component exceptions. Nil hooks preserve existing behavior; hooks do not synthesize model events or repair missing-node ordering. Document lifetimes, UI-thread execution, UTF-16/rune conversion and migration examples. No wire, dependency or other-backend changes.

The branch normally merges current main before the hook commit, retaining the original bounded-Stack change without rewriting history.

Validation:

• One temporary public Backend reproduction: an 897-DIP root with a 48-DIP header previously produced a 1280-DIP Scroll viewport; the same case now produces 849 DIPs. Red/green reproduced with the committed MyGo pin, and independently in the app consumer with published MyGo 6efea658. Temporary files deleted; no retained tests added.
• Existing intrinsic largest-child, removal/shrink, overlapping layers and z-order paint/press tests pass. Full Go package tests and race pass.
• Linux/amd64, Windows/amd64 and Darwin/arm64 builds and vet pass with CGO_ENABLED=0, both ordinary and mygo_noinspector builds. Race uses CGO_ENABLED=1.

The hook successor additionally passes full/race/vet, Linux/Windows/Darwin arm64 ordinary and production CGO0 build/vet, existing tooling/test_mygo.sh contracts/oracle/runtime checks, and published-module source/checksum verification. No retained tests or changed assertions were added.

In logseq/logseq#13900, the source-identical precommit consumer with published LUI 1f44501 and MyGo 6efea658 passes a scoped real-native/production-worker CmdK restore/reopen test: actual Page/0..4 and one-key replacement g/1..1; all restore command entries see the target input already created. That app separately fixes document patch publication ordering. This is not full product, wheel or OS IME acceptance; both PRs remain unmerged.

Link to Devin session: https://app.devin.ai/sessions/4a14d15bc6d44d18a9254cd088d5cc5e
Open in Devin Desktop: https://app.devin.ai/desktop/session/4a14d15bc6d44d18a9254cd088d5cc5e?variant=devin
Requested by: @tiensonqin

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring