fix(transform): #764 — module-init State() no longer breaks stateOnChange (v0.5.910)

[proggeramlug]

Summary

• Fixes Auto-bind reactive template literals in Text/TextField labels to perry_ui_state_bind_text_template #764 (and the underlying defect behind Reactive state in textfield not working #763): const cell = State("") at module-init level was hijacked by perry-transform's state_desugar pass — rewritten into the synthetic keyed runtime (__state_init + __state_set + __state_get) — while stateOnChange(cell, ...) / stateBindTextfield(cell, ...) / etc. were left untouched. The handle-based FFI saw undefined as its widget handle, the subscriber registry stayed empty, and the callback never fired. Same path was breaking the v0.5.112 reactive-Text(\…${state.value}…`)IIFE desugar wheneverState()` appears at module-init.
• Gate the rewrite so it only fires for bindings that no handle-based state API consumes. NavStack / ForEach / .set / .value / .get / .text rewrites (and lowercase state(...) flows from perry/ui: state→UI binding propagation only fires on --target harmonyos (deferred to v6.5) #535) are unchanged.
• Tests: 4 new state_desugar unit tests + 2 new integration fixtures under test-files/. Workspace tests green; perry/ui: TextField in non-initially-active NavStack route doesn't accept geisterhand /type after screen.set #640 NavStack regression check still passes.

Test plan

• cargo test --release -p perry-transform — 23/0/0, includes the 4 new gate tests.
• Full workspace tests (excluding cross-host UI crates per CLAUDE.md) — exit 0.
• test_issue_763_reactive_textfield.ts — AppleScript validation on macOS: typing into the TextField AND clicking the "set hello world" button both reactively update the standalone Text(\current state for text: ${text.value}`)` widget.
• test_issue_764_state_at_module_init.ts — CLI smoke: stateOnChange callback fires on every cell.set(...).
• perry/ui: TextField in non-initially-active NavStack route doesn't accept geisterhand /type after screen.set #640 NavStack regression: test_issue_640_navstack_textfield.ts still routes A↔B correctly.
• Windows path (the user's Reactive state in textfield not working #763 platform) — not yet validated here; the fix is purely in the platform-agnostic HIR transform layer so the symptom should resolve there too if the underlying cause matched. Worth a follow-up confirmation from the reporter.

Notes

• Version bump 0.5.909 → 0.5.910. CLAUDE.md + Cargo.toml + Cargo.lock + CHANGELOG entry included.
• New TS fixtures need --target macos to link perry-ui-macos, so they join test_issue_640_navstack_textfield in the compile-smoke SKIP_TESTS list.
• Auto-bind reactive template literals in Text/TextField labels to perry_ui_state_bind_text_template #764 was originally filed as a "wire Text(\…${state.value}…`)toperry_ui_state_bind_text_template" feature request, but investigation showed the IIFE-based auto-bind has shipped since v0.5.112 — the user-visible failure in #763 is actually this separate module-init regression. The runtime-side perry_ui_state_bind_text_template` consolidation is left as a future architectural improvement.