Correct misleading iOS archive-hang rationale (Crashlytics process group, not Gradle deadlock)

Co-authored-by: premnirmal <1255689+premnirmal@users.noreply.github.com>

iosApp/README.md

@@ -114,9 +114,12 @@ You do **not** need to build the shared framework separately or wire it up by ha
 project runs `./gradlew :shared:embedAndSignAppleFrameworkForXcode` as a scheme **Build pre-action**,
 which compiles and links the Kotlin/Native `Shared.framework` for the active configuration/SDK once,
 before either the app or the widget extension links it. (It is a single scheme pre-action rather than
-a per-target run-script phase on purpose: running the same Gradle framework build in **both** the app
+a per-target run-script phase on purpose: running the identical Gradle framework build in **both** the
-and the widget target made `xcodebuild archive` hang — the two concurrent Gradle invocations
+app and the widget target is redundant, so consolidating it into one up-front pre-action builds the
-deadlocked on Gradle's lock/daemon. See the comments in [`project.yml`](project.yml).) The App Groups
+framework a single time. Note this is a simplification, **not** the fix for the archive hang — the
+widget extension and both Gradle phases already existed at tag `4.1.000`. The "archive hangs at *Run
+custom shell script*" symptom was the synchronous Firebase Crashlytics dSYM upload staying in
+`xcodebuild`'s process group; see the Crashlytics notes below.) The App Groups
 capability (`group.com.github.premnirmal.ticker`) is applied to both targets from the committed
 `*.entitlements` files, so the app and widget share the `WidgetSnapshotStore` `NSUserDefaults` suite.
 

iosApp/project.yml

@@ -182,10 +182,12 @@ targets:
     # NOTE: the shared Kotlin/Native framework is NOT built by a per-target
     # run-script phase here. It is built ONCE by the scheme's Build pre-action
     # (see `schemes.StocksWidget.build.preActions` below), before either this app
-    # target or the widget extension links `-framework Shared`. Having the Gradle
+    # target or the widget extension links `-framework Shared`. Consolidating it
-    # `:shared:embedAndSignAppleFrameworkForXcode` phase in BOTH targets caused
+    # there avoids running the identical `:shared:embedAndSignAppleFrameworkForXcode`
-    # `xcodebuild archive` to hang (two concurrent Gradle builds of the same
+    # Gradle build twice (once per target) for the same framework. (This is a
-    # framework deadlocking on the Gradle lock/daemon) — see the pre-action.
+    # simplification, NOT the fix for the "archive hangs at Run custom shell
+    # script" problem — that was the synchronous Firebase Crashlytics dSYM upload
+    # staying in xcodebuild's process group; see the Firebase Crashlytics phase.)
 
   StockTickerWidget:
     type: app-extension
@@ -208,9 +210,10 @@ targets:
           - Shared
     # See the note on the StocksWidget app target above: the shared framework is
     # built ONCE by the scheme Build pre-action, not by a per-target run-script
-    # phase, so this extension does not run Gradle itself (which is what made
+    # phase, so this extension does not run Gradle itself (avoiding a redundant
-    # `xcodebuild archive` hang). It only links `-framework Shared` (built into
+    # second build of the same framework). It only links `-framework Shared`
-    # shared/build/xcode-frameworks/$CONFIGURATION/$SDK_NAME by that pre-action).
+    # (built into shared/build/xcode-frameworks/$CONFIGURATION/$SDK_NAME by that
+    # pre-action).
 
 schemes:
   StocksWidget:
@@ -220,12 +223,17 @@ schemes:
       # Build the shared Kotlin/Native `Shared.framework` ONCE, before Xcode
       # builds any target in the scheme. This replaces the old per-target
       # "Compile Kotlin/Native framework" run-script phases that lived in BOTH
-      # the app and the widget-extension target: during `xcodebuild archive`
+      # the app and the widget-extension target. Running the identical
-      # those two Gradle invocations of the same
+      # `:shared:embedAndSignAppleFrameworkForXcode` Gradle build in two targets
-      # `:shared:embedAndSignAppleFrameworkForXcode` task ran concurrently and
+      # is redundant (the second invocation just repeats or waits on the same
-      # deadlocked on Gradle's lock/daemon, so the archive hung at the widget's
+      # work); a single up-front pre-action builds the framework exactly once.
-      # "Compile Kotlin/Native framework" phase and never finished (it worked
+      # NOTE: this consolidation is a simplification, not the cure for the
-      # before the widget extension existed, when there was a single invocation).
+      # "archive hangs at Run custom shell script" symptom. Both the widget
+      # extension and these duplicate Gradle phases already existed at tag
+      # 4.1.000, so they did not introduce the hang. The hang was the synchronous
+      # Firebase Crashlytics dSYM upload lingering in `xcodebuild`'s process
+      # group (fixed in the Firebase Crashlytics phase via fork+setsid — see that
+      # script and iosApp/README.md).
       # A scheme Build pre-action runs a single time up front, so the framework
       # is present in shared/build/xcode-frameworks/$CONFIGURATION/$SDK_NAME
       # before either target links `-framework Shared`. Build pre-actions also