fix(ci): disable SPM at CI level instead of via pubspec flag - #2675

Audit by a second Claude agent surfaced four real gaps from the merge.
Closes them.

1. **#2672 / #2675 — iOS SPM disable + dSYM upload**
   - Add `upload_dsyms_to_crashlytics` private lane to
     `sample_app/ios/fastlane/Fastfile` and wire it into
     `distribute_to_firebase` and `distribute_to_testflight` before the
     Firebase/TestFlight upload. Without this lane the release Fastfile
     never uploads Crashlytics symbol files, so iOS crash reports stay
     unsymbolicated. Master moved this into the Fastfile itself.
   - Add `flutter config --no-enable-swift-package-manager` step to all
     three iOS install blocks in `distribute_external.yml` and
     `distribute_internal.yml`. This follows master's #2675 pattern
     (disable SPM at CI level, not via the now-removed `pubspec.yaml`
     `flutter.config` knob).

2. **#2653 — `maximumMessageLimit` API surface on the public view**
   - `MessageListCore` already exposed `maximumMessageLimit` /
     `retentionTrimBuffer`, but the public `StreamMessageListView`
     constructor did not forward them, so consumers couldn't enable
     trim without dropping down to `MessageListCore`. Add both
     parameters to `StreamMessageListView` and forward them at the
     `MessageListCore(...)` call site. Default for
     `retentionTrimBuffer` is inlined (`30`) because the canonical
     constant on `MessageRetentionGate` is `@visibleForTesting`.

3. **#2653 — `pruneOldest` LLC tests**
   - Port master's `group('\`.state.pruneOldest\`', ...)` (7 tests)
     into `channel_test.dart`. v10's `ChannelClientState.pruneOldest`
     was already present from the merge; only the regression tests
     were missing.

Not ported (intentionally):
- #2667's two duplicate-id regression tests
  (`should not duplicate when server echoes back…` and
  `should not duplicate when the locally-sent message is no longer
  the latest`). v10's `_updateMessages` keyed-map merge can't produce
  the duplicate shape these tests guard against, and porting them
  would require splicing into a v10 group with a different setUp.
- Master's `scrollPhysics` nullable default — v10's
  `ClampingScrollPhysics()` default is the documented v10 contract.
- Master's `updateMessage`-side `lastIndexWhere` fast path — v10
  rewrote the state-update path to a keyed-map merge (O(N+M))
  which is functionally equivalent.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

Restores what #2672 / #2675 worked around, rather than re-disabling SPM.

`FLUTTER_XCODE_CODE_SIGN_IDENTITY` / `..._PROVISIONING_PROFILE_SPECIFIER`
reach xcodebuild as command-line build settings, and those apply to every
target in the build graph. With CocoaPods that was harmless — podhelper.rb
sets `CODE_SIGNING_ALLOWED = NO` on pod resource bundles and on
Pods-Runner. Swift Package plugin bundles have no such hook, so they
inherited the app's manual identity and failed the archive with
`Signing for "<plugin>" requires a development team` — 40+ of them.

Writing the same two settings into Flutter/Signing.xcconfig instead fixes
it: Flutter/Release.xcconfig is the base configuration of the Runner
target alone (the project-level configurations have no xcconfig), and
Runner's Release config leaves identity and profile unset, so an xcconfig
can supply them. Verified locally via `fastlane ios build_ipa
export_method:"app-store"`: zero package signing errors, only the
expected missing distribution certificate. `no_codesign:true` still
archives successfully and removes any stale generated file.

The env-var approach itself is still needed in spirit because
flutter/flutter#113977 is open; only its scope changes.

Xcode selection moves to a shared .github/actions/setup-xcode, defaulting
to the newest Xcode on the image. The Fastfile no longer calls
`select_xcode` — it cannot express "latest", since it resolves to
/Applications/Xcode_<version>.app, and it was silently overriding the
workflows' own choice with a pinned 26.2 that the xcode-27 image does not
have. The two e2e jobs opt into 26.2 explicitly: they run on macos-15,
whose default is Xcode 16.4, and their pinned simulator runtimes need 26.x.

Co-Authored-By: Claude Opus 5 <[email protected]>

* chore(samples): adopt Xcode 27 and drop CocoaPods for iOS/macOS

Moves the sample app's iOS build to Swift Package Manager and removes
the CocoaPods integration from both the iOS and macOS Runner projects.

`media_kit_video` was the only remaining pod-only plugin. It backed
`SampleAppVideoPlayer`, whose desktop branch is gated on Windows/Linux —
platforms the sample app has no runner directories for — so on every
platform it can actually be built for the widget already fell through to
`DefaultStreamVideoPlayer`. Dropping the dependency leaves iOS, macOS,
Android and web behaviour unchanged and makes every remaining plugin
SPM-compatible.

macOS deployment target goes 11.5 -> 12.0, the floor Flutter 3.47
declares in its generated `FlutterMacOS.podspec` and uses in its own
app template; below it the build fails to resolve. The highest floor
any plugin asks for is 11.0.

CI iOS jobs move to the `xcode-27` runner image with `xcode-version:
latest`, and the "Disable Swift Package Manager" steps are gone — with
them the tool would regenerate a Podfile and link plugins through
CocoaPods again. The pod cache action is deleted along with its last
consumers; the SwiftPM equivalent is ~1.5 GB, too large to be worth
caching.

Co-Authored-By: Claude Opus 5 <[email protected]>

* fix(ci): scope iOS signing to the Runner target so SPM archives work

Restores what #2672 / #2675 worked around, rather than re-disabling SPM.

`FLUTTER_XCODE_CODE_SIGN_IDENTITY` / `..._PROVISIONING_PROFILE_SPECIFIER`
reach xcodebuild as command-line build settings, and those apply to every
target in the build graph. With CocoaPods that was harmless — podhelper.rb
sets `CODE_SIGNING_ALLOWED = NO` on pod resource bundles and on
Pods-Runner. Swift Package plugin bundles have no such hook, so they
inherited the app's manual identity and failed the archive with
`Signing for "<plugin>" requires a development team` — 40+ of them.

Writing the same two settings into Flutter/Signing.xcconfig instead fixes
it: Flutter/Release.xcconfig is the base configuration of the Runner
target alone (the project-level configurations have no xcconfig), and
Runner's Release config leaves identity and profile unset, so an xcconfig
can supply them. Verified locally via `fastlane ios build_ipa
export_method:"app-store"`: zero package signing errors, only the
expected missing distribution certificate. `no_codesign:true` still
archives successfully and removes any stale generated file.

The env-var approach itself is still needed in spirit because
flutter/flutter#113977 is open; only its scope changes.

Xcode selection moves to a shared .github/actions/setup-xcode, defaulting
to the newest Xcode on the image. The Fastfile no longer calls
`select_xcode` — it cannot express "latest", since it resolves to
/Applications/Xcode_<version>.app, and it was silently overriding the
workflows' own choice with a pinned 26.2 that the xcode-27 image does not
have. The two e2e jobs opt into 26.2 explicitly: they run on macos-15,
whose default is Xcode 16.4, and their pinned simulator runtimes need 26.x.

Co-Authored-By: Claude Opus 5 <[email protected]>

* fix(ci): find Crashlytics upload-symbols in the Swift Package checkout

`upload_dsyms_to_crashlytics` pointed `binary_path` at
ios/Pods/FirebaseCrashlytics/upload-symbols, which no longer exists now
that the sample app has no CocoaPods integration. Both iOS distribute
jobs archived, signed and exported their IPAs successfully and then died
here:

    [!] Couldn't find file at path
        '.../sample_app/ios/Pods/FirebaseCrashlytics/upload-symbols'

Under Swift Package Manager the binary lives in the firebase-ios-sdk
checkout instead. fastlane's own discovery only searches Pods/ and
Fabric.app, so the path is globbed and passed explicitly, with a clear
error if it moves again.

Co-Authored-By: Claude Opus 5 <[email protected]>

* docs(ci): correct why the e2e jobs pin Xcode 26.2

The comment claimed macos-15 defaults to Xcode 16.4 and therefore needs a
26.x toolchain. The image default is indeed 16.4, but setup-xcode's
'latest' resolves to the newest Xcode installed, which on macos-15 is
26.3 — so that was never the reason.

The actual constraint is runtime alignment: macos-15 ships iOS simulator
runtimes 18.5, 18.6, 26.0, 26.1 and 26.2, but no 26.3.

Co-Authored-By: Claude Opus 5 <[email protected]>

* chore(samples): make the example apps buildable again, without CocoaPods

The per-package examples pinned deployment targets far below what Flutter
3.47 supports, so none of them could build. Raises iOS to 15.0 and macOS
to 12.0 — the values Flutter's own app template uses, and for macOS the
floor its generated FlutterMacOS.podspec declares, below which `pod
install` refuses to resolve.

Four Podfiles also declared a `RunnerTests` target that no project
defines, which failed `pod install` outright:

    [!] Unable to find a target named `RunnerTests` in project
        `Runner.xcodeproj`, did find `Runner`.

stream_chat_flutter's two Podfiles already had that stanza commented out,
which is why only those examples still built.

Every plugin these examples use is a Swift Package, so Flutter resolved
them all through SPM and then asked for CocoaPods to be removed by hand:

    All plugins found for ios are Swift Packages, but your project still
    has CocoaPods integration. [...] will need to be migrated to Swift
    Package Manager manually.

Done here, so the six Podfiles are gone rather than fixed: `pod
deintegrate` on each project, Podfiles deleted, `Pods-Runner` includes
stripped from all twelve xcconfigs, and `Pods/Pods.xcodeproj` dropped
from the workspaces. Some of those includes were a hard `#include`, so
removing the Pods directory alone would have broken the build outright.

Building each example also applied Flutter 3.47's pending project
migrations — `@main`, `FlutterImplicitEngineDelegate`,
`UIApplicationSceneManifest`, and dropping the stale `MinimumOSVersion`
from AppFrameworkInfo.plist.

All seven configurations verified from a wiped build directory on Xcode
27.0 / Flutter 3.47.0 — no Podfile regenerated, no `pod install`, and no
migration warning: stream_chat, stream_chat_flutter,
stream_chat_flutter_core, stream_chat_localizations and
stream_chat_persistence on iOS, plus stream_chat_flutter and
stream_chat_persistence on macOS.

Co-Authored-By: Claude Opus 5 <[email protected]>

* docs(ci): trim rationale out of code comments

Keeps the mechanism a future reader needs to avoid reintroducing the bug,
drops the history and the point-in-time cache measurements — those belong
in the pull request.

Co-Authored-By: Claude Opus 5 <[email protected]>

* fix(ci): do not fail a release when the dSYM upload path is missing

upload_dsyms_to_crashlytics runs after build_ipa but before
firebase_app_distribution and upload_to_testflight, so a missed glob
aborted an already-built, signed release over a symbol upload. Both the
SourcePackages directory and the firebase-ios-sdk checkout name can move
under a Flutter or Firebase bump.

Symbols can be uploaded after the fact; a failed release costs a full
rebuild. Logs an error and skips instead.

Co-Authored-By: Claude Opus 5 <[email protected]>

---------

Co-authored-by: Claude Opus 5 <[email protected]>