refactor: add tanstack signal tanstack plugin, reorder files (@miodec)

[Miodec]

No description provided.

[Copilot]

Pull request overview

Refactors frontend dev tooling by moving DevTools into a dedicated components/dev area and extending TanStack devtools with a custom “Core Signals” plugin to inspect app state.

Changes:

• Export modalState store and wire it into a new signals devtools plugin.
• Add components/dev/DevTools.tsx that lazy-loads TanStack devtools + dev options modal + Solid overlay only in import.meta.env.DEV.
• Update mount to import DevTools from the new dev path and register the new plugin in TanStack devtools.

Reviewed changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
frontend/src/ts/states/modals.ts	Exports modal store tuple for external inspection (devtools).
frontend/src/ts/components/mount.tsx	Points DevTools import to the new components/dev location.
frontend/src/ts/components/dev/TanstackDevtools.tsx	Registers the new signals plugin alongside existing devtools plugins.
frontend/src/ts/components/dev/SignalsDevtools.tsx	Adds “Core Signals” plugin UI for browsing key app signals/stores.
frontend/src/ts/components/dev/DevTools.tsx	Adds DEV-only lazy-loaded dev tooling container (TanStack devtools + overlay + modal).

[Copilot]

Exporting setModalState makes the internal modal-store mutation API public (and it's not imported anywhere else). Prefer keeping the setter module-private and export only a read-only selector (or modalState alone) for devtools to avoid widening the state API surface.

[Copilot]

formatValue returns JSON.stringify(value) which is typed as string | undefined and can also throw (BigInt/circular refs). Under strict this won’t typecheck and can crash the panel. Ensure this branch always returns a string (e.g., try/catch + fallback to String(value) when stringify fails/returns undefined).

Suggested change

	return JSON.stringify(value);
	try {
	const json = JSON.stringify(value);
	if (typeof json === "string") return json;
	} catch {
	// ignore and fall through to String(value)
	}
	return String(value);

[Copilot]

setTimeout in the reactive effect isn’t cleared on component cleanup, so unmounting the panel can leave pending timers and set state after unmount. Store the timeout id and cancel it in onCleanup (or use a debounced signal).

[github-actions]

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