Implement ConcurrentRequestStrategy to support awaiting in-flight requests.

[colinrtwhite]

Minor tweaks (naming, param order, binary compatibility fixes, extra tests) to @luciofm's work to implement concurrent request handling (thank you!). Full credit to him.

[Copilot]

Pull request overview

This PR introduces a ConcurrentRequestStrategy abstraction and wires it into NetworkFetcher (and the OkHttp/Ktor factories) to coordinate concurrent network requests for the same resource, including a de-duping strategy that allows waiters to resume after the leader finishes.

Changes:

• Add ConcurrentRequestStrategy + DeDupeConcurrentRequestStrategy and comprehensive unit tests for coordination behavior.
• Update NetworkFetcher to apply a configurable concurrency strategy keyed by the disk cache key, and adjust constructor/factory wiring (including binary-compat shims).
• Update OkHttp/Ktor factory APIs and network fetcher tests to pass through ConcurrentRequestStrategy.

Reviewed changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
internal/test-utils/src/commonMain/kotlin/coil3/test/utils/AbstractNetworkFetcherTest.kt	Adds an integration-style test verifying de-duping results in 1 network fetch + remaining disk reads.
coil-network-okhttp/src/commonTest/kotlin/coil3/network/okhttp/OkHttpNetworkFetcherTest.kt	Updates test factory creation to inject a ConcurrentRequestStrategy.
coil-network-okhttp/src/commonMain/kotlin/coil3/network/okhttp/OkHttpNetworkFetcher.kt	Adds a new OkHttpNetworkFetcherFactory overload that accepts concurrentRequestStrategy while keeping hidden binary-compat overload.
coil-network-okhttp/api/jvm/coil-network-okhttp.api	Updates JVM API surface to reflect the new factory overload(s).
coil-network-okhttp/api/android/coil-network-okhttp.api	Updates Android API surface to reflect the new factory overload(s).
coil-network-ktor3/src/commonTest/kotlin/coil3/network/ktor3/KtorNetworkFetcherTest.kt	Updates test factory creation to pass a ConcurrentRequestStrategy.
coil-network-ktor3/src/commonMain/kotlin/coil3/network/ktor3/KtorNetworkFetcher.kt	Adds overloads to accept concurrentRequestStrategy and keeps hidden binary-compat overloads.
coil-network-ktor3/api/jvm/coil-network-ktor3.api	Updates JVM API surface for new Ktor factory overload(s).
coil-network-ktor3/api/coil-network-ktor3.klib.api	Updates KLIB API surface for new Ktor factory overload(s).
coil-network-ktor3/api/android/coil-network-ktor3.api	Updates Android API surface for new Ktor factory overload(s).
coil-network-ktor2/src/commonTest/kotlin/coil3/network/ktor2/KtorNetworkFetcherTest.kt	Updates test factory creation to pass a ConcurrentRequestStrategy.
coil-network-ktor2/src/commonMain/kotlin/coil3/network/ktor2/KtorNetworkFetcher.kt	Adds overloads to accept concurrentRequestStrategy and keeps hidden binary-compat overloads.
coil-network-ktor2/api/jvm/coil-network-ktor2.api	Updates JVM API surface for new Ktor factory overload(s).
coil-network-ktor2/api/coil-network-ktor2.klib.api	Updates KLIB API surface for new Ktor factory overload(s).
coil-network-ktor2/api/android/coil-network-ktor2.api	Updates Android API surface for new Ktor factory overload(s).
coil-network-core/src/commonTest/kotlin/coil3/network/NetworkFetcherTest.kt	Updates NetworkFetcher tests for the new constructor signature (lazy connectivity + strategy).
coil-network-core/src/commonTest/kotlin/coil3/network/ConcurrentRequestStrategyTest.kt	Adds new tests covering uncoordinated vs de-duped concurrency semantics and failure/cancellation behavior.
coil-network-core/src/commonMain/kotlin/coil3/network/NetworkFetcher.kt	Wires ConcurrentRequestStrategy into fetch execution and updates factory/constructor (with hidden binary-compat constructor).
coil-network-core/src/commonMain/kotlin/coil3/network/ConcurrentRequestStrategy.kt	Introduces ConcurrentRequestStrategy and a de-dupe implementation backed by keyed coordination.
coil-network-core/api/jvm/coil-network-core.api	Updates JVM API surface for new strategy + updated NetworkFetcher/Factory signatures.
coil-network-core/api/android/coil-network-core.api	Updates Android API surface (currently appears inconsistent with source).

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[Copilot]

Pull request overview

Copilot reviewed 22 out of 22 changed files in this pull request and generated no new comments.

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[luciofm]

Thanks @colinrtwhite 😄 , I was planning to get back to it but you beat me...

Did some testing and all look good to me