docs(telemetry): replace the non-existent default CMake preset

Every telemetry build instruction told the reader to run
`cmake --preset default`. No `CMakePresets.json` is tracked in the repo, and the
only preset that exists is `conan-release`, generated into the gitignored
`CMakeUserPresets.json` by `conan install`. So the documented first build step
fails before it starts, in the runbook's quick-start, its disable procedure, and
the telemetry stack's testing guide.

Replaced with the flow BUILD.md actually documents -- `conan install ..
--output-folder .` followed by an explicit `conan_toolchain.cmake` invocation --
with `-o telemetry=True` / `-Dtelemetry=ON` as the telemetry delta, and a note
that `--preset conan-release` works as a shorthand.

OpenTelemetryPlan/Phase2_taskList.md

@@ -111,7 +111,7 @@ These can be added later if dashboard queries specifically need them. The node h
 **Verification Checklist**:
 
 - [ ] `conan install . --build=missing -o telemetry=True` succeeds
-- [ ] `cmake --preset default -Dtelemetry=ON` configures correctly
+- [ ] `cmake -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake -Dtelemetry=ON ..` configures correctly (there is no `default` preset; Conan writes `conan-release`)
 - [ ] Build succeeds with telemetry ON
 - [ ] Build succeeds with telemetry OFF
 - [ ] Existing tests pass with telemetry ON

docker/telemetry/TESTING.md

@@ -10,12 +10,16 @@ pipeline end-to-end, from span generation through the observability stack
 
 ### Build xrpld with telemetry
 
+Follow [BUILD.md](../../BUILD.md) with `-o telemetry=True` added. From a build directory (`.build/`):
+
 ```bash
-conan install . --build=missing -o telemetry=True
-cmake --preset default -Dtelemetry=ON
-cmake --build --preset default --target xrpld
+conan install .. --output-folder . --build missing -o telemetry=True --settings build_type=Release
+cmake -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake -DCMAKE_BUILD_TYPE=Release -Dxrpld=ON -Dtelemetry=ON ..
+cmake --build . --target xrpld
 ```
 
+Conan also writes a `conan-release` preset, so `cmake --preset conan-release -Dtelemetry=ON` works too. There is no preset named `default`.
+
 The binary is at `.build/xrpld`.
 
 ### Required tools

docs/telemetry-runbook.md

@@ -79,12 +79,16 @@ endpoint=http://localhost:4318/v1/traces
 
 ### 3. Build with telemetry support
 
+Follow [BUILD.md](../BUILD.md), adding `-o telemetry=True` so Conan pulls `opentelemetry-cpp`. From a build directory (`.build/`):
+
 ```bash
-conan install . --build=missing -o telemetry=True
-cmake --preset default -Dtelemetry=ON
-cmake --build --preset default
+conan install .. --output-folder . --build missing -o telemetry=True --settings build_type=Release
+cmake -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake -DCMAKE_BUILD_TYPE=Release -Dxrpld=ON -Dtelemetry=ON ..
+cmake --build . --target xrpld
 ```
 
+Conan also writes a `conan-release` CMake preset, so `cmake --preset conan-release -Dtelemetry=ON` works instead of the explicit toolchain line. There is no preset named `default`.
+
 ### 4. Run against a live network
 
 Two ready-made configs connect a tracking node (no validator credentials) to a
@@ -3316,8 +3320,8 @@ Set `enabled=0` in the `[telemetry]` config section (runtime disable, no rebuild
 compile telemetry out:
 
 ```bash
-conan install . --build=missing -o telemetry=False
-cmake --preset default -Dtelemetry=OFF
+conan install .. --output-folder . --build missing -o telemetry=False --settings build_type=Release
+cmake -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake -DCMAKE_BUILD_TYPE=Release -Dtelemetry=OFF ..
 ```
 
 Pass the flag explicitly rather than omitting it — an omitted flag resolves to whatever