fix(act): give every Act its own ports frame

[Rotorsoft]

Closes #1597.

A shared Act could write its events into a tenant's store. If a scoped Act's reaction handler dispatched into a shared one, the shared Act resolved store() and cache() through the tenant's frame and committed there instead of to the global log. Silently, and permanently — events in the wrong log never move.

What went wrong

A scoped Act reads its ports from an ambient frame. An Act built without ActOptions.scoped read the process-wide adapters, and make_run_scoped gave it a bare (fn) => fn() on the grounds that "a singleton Act needs no frame at all".

That is true only when nobody else is holding a frame. Calling fn() does not leave one, so a shared Act called from inside a tenant's handler inherited the tenant's ports.

The fix

Every Act enters a frame. The one built without a bag carries the singleton adapters.

this._ports = options.scoped ?? default_scope();
this._scoped = make_run_scoped(this._ports);

There is no longer a path that inherits someone else's ports: a shared Act resolves to the singleton adapters wherever it is called from, and a tenant Act keeps resolving to its own bag as it already did. One rule, no special case — the branch that made "unscoped" mean "whatever frame I am standing in" is gone.

Two details in default_scope:

• The bag reads through getters, not captured values. The adapters resolve lazily and store(new PgStore()) in application setup runs before build(), so a bag that captured them when it was made would pin whatever existed at construction.
• It reads the raw resolvers, not the public store()/cache(). Those consult the frame this bag is, and would recurse.

What it costs

Nothing measurable. On the in-repo scope-overhead bench, at the level of a real Act operation:

	unscoped (no-op wrap)	scoped (real scoped.run wrap)
mean	2.4116 ms	2.3925 ms
second case	1.2256 ms	1.2412 ms

Both inside the noise — the AsyncLocalStorage entry is roughly 150 ns against work measured in milliseconds. Port lookups inside a frame do cost more than outside one (about 200 ns against 50 ns), which every scoped Act already paid; a handful per operation does not show up either.

What this replaces

The first version of this branch refused the combination instead: building an Act of one kind while an Act of the other kind was live threw. It worked and the whole suite passed, but it made coexistence illegal, and coexistence is documented and used — docs/docs/architecture/extension-points.md:330 blesses "an empty Act wrapping a raw store for tooling" beside scoped tenant Acts, and both example apps built their Act at module scope, so importing a file for its builder decided the port strategy for the whole process. Landing it meant restructuring both examples, a recipe, a test helper, and an act-diagram fixture.

Putting the unscoped Act in a default scope fixes the same bug in the framework, with no migration and nothing to remember. The examples are untouched.

The narrower scoped.exit the issue proposed would also have worked, but it fixes the singleton path by making it undo something, where this makes both paths the same thing.

Test plan

• libs/act/test/default-scope.spec.ts — a shared Act called from inside a tenant's handler writes to the shared store; a tenant Act called from inside a shared handler writes to the tenant store; a call outside any Act still sees the singleton adapters; an adapter injected before build() is the one used
• pnpm test — 3614 passing
• 100% coverage on statements, branches, functions and lines
• pnpm typecheck clean across the workspace, biome clean, architecture spec passing
• CI green
• Review

Stability charter impact

No public surface changed. ActOptions.scoped keeps its shape and meaning; default_scope is @internal in ports.ts, beside the resolvers it reads. current_ports() now returns a bag for every call made inside an Act rather than only inside a scoped one — internal, and its doc-comment says so.

rfc-gate: exempt — the stability snapshot grew from the new internal helper and its doc comments. No public surface was added.

Found by

Debug wave 21, reproduced in the main loop.

[github-actions]

🎉 This PR is included in version @rotorsoft/act-v1.31.15 🎉

The release is available on:

• @rotorsoft/act-v1.31.15
• GitHub release

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[github-actions]

🎉 This PR is included in version @rotorsoft/act-tck-v1.36.16 🎉

The release is available on:

• @rotorsoft/act-tck-v1.36.16
• GitHub release

Your semantic-release bot 📦🚀