feat(container): add scoped bindings

[osbre]

Adds a new scoped lifetime (Container::scoped() and #[Scoped]) for dependencies that live for a single request or lifecycle, replacing the manual RouterReset workaround from #2278.

Problem

Tempest previously supported only transient and singleton lifetimes. State that is valid for a single request or job - such as MatchedRoute, tenant contexts, or authenticated users - had no native lifetime representation.

This resulted in cross-request leaks or clumsy workarounds, such as RouterReset and custom Resettable implementations, forcing every package holding per-request state to write its own manual cleanup logic.

Solution

• Introduces a third lifetime, available via container method or attribute:

$container->scoped(MatchedRoute::class, $matchedRoute);
$container->scoped(TenantContext::class, fn () => new TenantContext(...));

#[Scoped]
final class TenantContext { /* ... */ }

• Scoped bindings act like singletons during a single lifecycle and are cleared when Container::reset() is called.
• Definitions vs. Instances on Reset: Callable definitions are kept so they can provide fresh instances in the next lifecycle. Concrete instances cannot be rebuilt, so their bindings are removed entirely.
• #[Scoped] is supported everywhere #[Singleton] is: on autowired classes, on initializer classes, and on initialize() methods, including the tagged variant #[Scoped(tag: 'web')].
• Re-registering a scoped dependency with singleton() clears its scoped registration, so an explicit singleton always survives a reset.
• container:show lists scoped bindings under their own section, instead of mixing them into the singletons.
• MatchRouteMiddleware now binds MatchedRoute as scoped, and RouterReset has been deleted.
• Documented in docs/1-essentials/05-container.md.

Design Choices

• Defaults remain untouched: Transient stays the default strategy, and singletons are unmodified.
• Explicit naming: Chose dedicated scoped() and #[Scoped] declarations rather than hiding behavior behind boolean flags on singleton methods.
• Scope boundaries: Container::reset() is still only triggered via FrameworkKernel::shutdown(). This PR introduces the binding mechanism, leaving automatic scope creation per request/job for a future update. This is also why MatchRouteMiddleware keeps the unregister() call from fix(router): clear the matched route between requests #2278: two requests within a single test share a container without a reset in between.

Tests

Added 8 tests in ContainerTest covering:

1. Sharing within a lifecycle
2. Discarding an instance on reset
3. Discarding a tagged instance on reset
4. Keeping a callable definition across a reset
5. Leaving plain singletons untouched
6. Re-registering a scoped dependency as a singleton
7. The #[Scoped] attribute
8. A tagged #[Scoped] initializer

Plus one integration test asserting container:show lists scoped bindings separately.

[github-actions]

Benchmark Results

Comparison of feat/scoped-container-bindings against 3.x (16a1a2a6db94d90ca803ae4442520b880813d4e5).

Open to see the benchmark results

Benchmark	Set	Mem. Peak	Time	Variability
ContainerBench(benchAutowireSimple)	-	4.083mb +0.37%	4.835μs +12.07%	±0.81% +26.50%
ContainerBench(benchAutowireNested)	-	4.160mb +0.31%	15.916μs +5.88%	±0.47% -60.48%
ContainerBench(benchRegisterSingletonInstance)	-	6.106mb +4.26%	1.952μs +20.78%	±1.09% -44.96%
ContainerBench(benchRegisterDefinition)	-	6.776mb +3.84%	1.911μs +15.04%	±1.51% +72.81%
ContainerBench(benchResolveWithInitializer)	-	4.123mb +0.28%	7.165μs +9.73%	±0.87% -14.60%
ContainerBench(benchRegisterInitializer)	-	6.419mb +6.12%	5.227μs +10.51%	±0.86% -36.72%
ContainerBench(benchResolveWithDynamicInitializer)	-	4.127mb +0.21%	5.162μs +11.72%	±0.43% -74.86%
ContainerBench(benchRegisterDynamicInitializer)	-	6.244mb +5.22%	2.683μs +13.69%	±0.53% -53.68%
ContainerBench(benchRegisterClosureSingleton)	-	6.453mb +4.03%	1.993μs +16.16%	±0.66% +12.08%
ContainerBench(benchInvokeClosure)	-	4.134mb +0.24%	11.302μs +5.09%	±0.73% +23.27%

_{Generated by phpbench against commit a9fdc72}