Replace runtime discovery with static observation

[sonmbol]

What changed

• Replaced Objective-C/SKIE runtime state-flow discovery with compile-time-generated, statically typed observation plans.
• Added dedicated core, SKIE, NativeCoroutines, and macro targets with single-responsibility source files.
• Added shared per-model observation hubs so multiple SwiftUI consumers reuse one collection and duplicate values are suppressed before invalidation.
• Preserved StateObject factory laziness so repeated SwiftUI view-value construction does not allocate throwaway Kotlin ViewModels.
• Hardened ownership, rebinding, reentrant cancellation, failure routing, optional-child observation, and writable projected bindings.
• Reorganized the DailyPulse examples and updated package documentation, DocC, API checks, CI configuration, and changelog.
• Added macro, lifecycle, cancellation, concurrency, deduplication, rebinding, laziness, and performance coverage.

Why

Runtime selector discovery was expensive, fragile across generated ABI changes, and unable to provide compile-time guarantees. Eager factory evaluation also violated StateObject lifetime semantics by constructing a new Kotlin model whenever a parent recreated the SwiftUI view value.

The new architecture makes observation routes explicit and type-checked while preserving SwiftUI identity through stable, lazily realized StateObject storage. Shared hubs use allocation-light integer listener IDs, support reentrant teardown, and deregister from the weak registry in constant time.

Impact

Applications declare observable KMP ViewModels once with @KMPObservable. SwiftUI owners and observers retain native APIs while gaining deterministic teardown, shared collection, fewer redundant invalidations, and exporter-specific integration modules.

This intentionally changes the automatic-observation integration surface for the next major version; explicit adapters remain available as an exporter-neutral fallback.

Validation

• swift test -Xswiftc -strict-concurrency=complete -Xswiftc -warnings-as-errors — 36 tests passed
• xcodebuild docbuild -scheme KMPObservableBridge -destination 'generic/platform=iOS Simulator' CODE_SIGNING_ALLOWED=NO — passed
• swift package dump-package — passed
• ./Scripts/check-api.sh — passed (API baseline is not configured)
• Runtime-interception source audit — passed
• git diff --check — passed
• Release performance guardrails remain in the prior steady-state range after warm-up