Fix CI: split telemetry workflow into build + validate jobs

The telemetry validation pipeline was building all Conan dependencies
from source instead of fetching pre-built binaries. Root cause: the
workflow ran on ubuntu-latest natively, where the system compiler
configuration (gcc-13 on Ubuntu 24.04) produced different Conan
package IDs than the pre-built packages in the XRPLF Conan remote.

Fix by splitting into two jobs:
1. build-xrpld: runs on a self-hosted runner inside the same
   debian-bookworm-gcc-13 container the main CI uses, ensuring
   Conan package IDs match and ccache hits the remote cache.
2. validate-telemetry: runs on ubuntu-latest (which has Docker)
   to launch the telemetry stack and validate end-to-end.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/telemetry-validation.yml

@@ -11,15 +11,14 @@
 # services, runs a multi-node cluster) — it validates the full telemetry
 # stack end-to-end rather than individual unit tests.
 #
-# The build steps mirror the main CI pipeline (reusable-build-test-config.yml):
-#   - setup-conan action → build-deps action → cmake configure → cmake build
-# This ensures dependency resolution, toolchain generation, and compiler
-# flags are identical to what the PR workflow uses.
-#
-# NOTE: Unlike the main CI, this workflow runs natively on ubuntu-latest
-# (not in a container), so we cannot use XRPLF/actions/prepare-runner
-# which assumes /root paths. Instead we replicate the relevant setup
-# steps inline.
+# Architecture: two jobs to leverage cached dependencies:
+#   1. build-xrpld — runs on a self-hosted runner inside the same container
+#      image the main CI uses (debian-bookworm-gcc-13). This ensures Conan
+#      packages are fetched from the XRPLF remote instead of built from
+#      source, and ccache hits the remote cache.
+#   2. validate-telemetry — runs on ubuntu-latest (which has Docker) to
+#      launch the telemetry stack (OTel collector, Prometheus, Tempo, etc.)
+#      and validate the full pipeline end-to-end.
 
 name: Telemetry Validation
 
@@ -63,37 +62,38 @@ concurrency:
   group: telemetry-validation-${{ github.ref }}
   cancel-in-progress: true
 
+defaults:
+  run:
+    shell: bash
+
 env:
   BUILD_DIR: build
-  # ccache configuration — mirrors reusable-build-test-config.yml
-  CCACHE_NAMESPACE: telemetry-validation
-  CCACHE_REMOTE_ONLY: true
-  CCACHE_REMOTE_STORAGE: http://cache.dev.ripplex.io:8080|layout=bazel
-  CCACHE_SLOPPINESS: include_file_ctime,include_file_mtime
 
 jobs:
-  validate-telemetry:
-    name: Telemetry Stack Validation
-    runs-on: ubuntu-latest
-    timeout-minutes: 90
-
+  # ── Job 1: Build xrpld in the same container the main CI uses ──────
+  # This ensures Conan binary packages are fetched from the XRPLF remote
+  # (matching package IDs) and ccache hits the remote compilation cache.
+  build-xrpld:
+    name: Build xrpld
+    runs-on: [self-hosted, Linux, X64, heavy]
+    container: ghcr.io/xrplf/ci/debian-bookworm:gcc-13-sha-ab4d1f0
+    timeout-minutes: 60
+    env:
+      CCACHE_NAMESPACE: telemetry-validation
+      CCACHE_REMOTE_ONLY: true
+      CCACHE_REMOTE_STORAGE: http://cache.dev.ripplex.io:8080|layout=bazel
+      CCACHE_SLOPPINESS: include_file_ctime,include_file_mtime
     steps:
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
-      - name: Install system dependencies
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y curl jq bc ninja-build ccache
-
-      - name: Install Conan and Python dependencies
-        run: |
-          pip3 install conan
-          pip3 install -r docker/telemetry/workload/requirements.txt
+      - name: Prepare runner
+        uses: XRPLF/actions/prepare-runner@2cbf481018d930656e9276fcc20dc0e3a0be5b6d
+        with:
+          enable_ccache: ${{ github.repository_owner == 'XRPLF' }}
 
       - name: Print build environment
         uses: ./.github/actions/print-env
-        continue-on-error: true
 
       - name: Get number of processors
         uses: XRPLF/actions/get-nproc@cf0433aa74563aead044a1e395610c96d65a37cf
@@ -101,26 +101,15 @@ jobs:
         with:
           subtract: 2
 
-      # ── Build steps (mirrors main CI: setup-conan → build-deps → cmake) ──
-
       - name: Setup Conan
         uses: ./.github/actions/setup-conan
 
-      - name: Log into Conan remote
-        if: ${{ github.repository == 'XRPLF/rippled' }}
-        env:
-          CONAN_USER: ${{ secrets.CONAN_REMOTE_USERNAME }}
-          CONAN_PASS: ${{ secrets.CONAN_REMOTE_PASSWORD }}
-        run: conan remote login xrplf "$CONAN_USER" --password "$CONAN_PASS"
-
-      - name: Enable optimized binary compatibility
-        run: echo "core.graph:compatibility_mode=optimized" >> "$(conan config home)/global.conf"
-
       - name: Build dependencies
         uses: ./.github/actions/build-deps
         with:
           build_nproc: ${{ steps.nproc.outputs.nproc }}
           build_type: Release
+          log_verbosity: verbose
 
       - name: Configure CMake
         working-directory: ${{ env.BUILD_DIR }}
@@ -129,8 +118,6 @@ jobs:
             -G Ninja \
             -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake \
             -DCMAKE_BUILD_TYPE=Release \
-            -DCMAKE_C_COMPILER_LAUNCHER=ccache \
-            -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
             ..
 
       - name: Build xrpld
@@ -145,12 +132,40 @@ jobs:
             --target xrpld
 
       - name: Show ccache statistics
+        if: ${{ github.repository_owner == 'XRPLF' }}
         run: ccache --show-stats -vv
 
-      # ── Telemetry validation steps ──
+      - name: Upload xrpld binary
+        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
+        with:
+          name: xrpld-telemetry
+          path: ${{ env.BUILD_DIR }}/xrpld
+          retention-days: 1
+          if-no-files-found: error
 
-      - name: Make scripts executable
-        run: chmod +x docker/telemetry/workload/*.sh
+  # ── Job 2: Run telemetry validation on ubuntu-latest (has Docker) ──
+  validate-telemetry:
+    name: Telemetry Stack Validation
+    needs: build-xrpld
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Install Python dependencies
+        run: pip3 install -r docker/telemetry/workload/requirements.txt
+
+      - name: Download xrpld binary
+        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+        with:
+          name: xrpld-telemetry
+          path: ${{ env.BUILD_DIR }}
+
+      - name: Make binaries and scripts executable
+        run: |
+          chmod +x ${{ env.BUILD_DIR }}/xrpld
+          chmod +x docker/telemetry/workload/*.sh
 
       - name: Run full telemetry validation
         id: validation