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+# THROWAWAY DIAGNOSTIC — delete this file and its branch once the question is answered.
+#
+# Settles one claim that could not be settled from a dev machine: the shipped v1.10.0
+# whisper-stt-server carries 9 STRONG undefined references to libc++ symbols that the
+# SDK's own availability header dates to macOS 15.4
+# (`availability(macos, strict, introduced = 15.4)` on the bad_function_call key
+# function). If that annotation means what it says, the STT helper cannot load on any
+# macOS below 15.4 — which is Ventura and Sonoma, not just the Monterey case in #515,
+# and macOS 14 is the version the README recommends.
+#
+# Nobody on the project has a pre-15.4 Mac and no SDK older than 15.4 is installed to
+# prove the symbols absent, so the claim has stood as a strong inference. `macos-14` is
+# a Sonoma runner and settles it by simply trying to run the binary.
+#
+# This does NOT need a model or a recording: dyld resolves symbols at exec, so the
+# helper's own "--model is required" usage error already proves it loaded.
+
+name: diag-libcpp-floor
+
+on:
+  push:
+    branches: [claude/diag-libcpp-15-4]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  shipped-stt-on-sonoma:
+    runs-on: macos-14
+    steps:
+      - name: Record the exact OS under test
+        run: |
+          sw_vers
+          echo "arch: $(uname -m)"
+
+      - name: Fetch the shipped v1.10.0 arm64 build
+        run: |
+          curl -fsSL -o app.zip \
+            https://github.com/getopenscreen/openscreen/releases/download/v1.10.0/Openscreen-Mac-arm64-1.10.0.zip
+          ditto -x -k app.zip extracted
+          xattr -dr com.apple.quarantine extracted || true
+          BIN_DIR="$(dirname "$(find extracted -name whisper-stt-server -type f | head -1)")"
+          echo "BIN_DIR=$BIN_DIR" >> "$GITHUB_ENV"
+          ls -la "$BIN_DIR" | head -20
+
+      - name: What the shipped binary declares and imports
+        run: |
+          cd "$BIN_DIR"
+          echo "--- deployment target ---"
+          vtool -show-build whisper-stt-server | grep -E 'platform|minos|sdk'
+          echo "--- strong undefined refs to the 15.4-gated libc++ symbols ---"
+          nm -m whisper-stt-server | grep undefined | grep -E 'bad_function_callE' || echo "  (none)"
+          echo "count: $(nm -m whisper-stt-server | grep undefined | grep -c 'bad_function_callE')"
+
+      # THE TEST. Exit 0 or the usage error => it loaded, the claim is WRONG.
+      # `dyld: Symbol not found` => it could not load, the claim is RIGHT.
+      - name: Try to run it
+        id: run
+        continue-on-error: true
+        run: |
+          cd "$BIN_DIR"
+          set +e
+          ./whisper-stt-server --help > out.txt 2> err.txt
+          echo "exit=$?" | tee -a "$GITHUB_OUTPUT"
+          echo "--- stdout ---"; cat out.txt
+          echo "--- stderr ---"; cat err.txt
+
+      - name: Verdict
+        run: |
+          cd "$BIN_DIR"
+          if grep -qiE 'symbol not found|dyld' err.txt; then
+            echo "CLAIM CONFIRMED: the shipped STT helper cannot load on $(sw_vers -productVersion)."
+            grep -iE 'symbol not found|dyld|Referenced from|Expected in' err.txt | head -5
+          elif grep -qiE 'model|usage' out.txt err.txt; then
+            echo "CLAIM REFUTED: the shipped STT helper loads and runs on $(sw_vers -productVersion)."
+          else
+            echo "INCONCLUSIVE — neither a loader error nor the usage message. Read the logs above."
+          fi