docs(sim_sih): link Hawkeye visualizer, add stub page (#27159)

* docs(sim_sih): link Hawkeye visualizer, add stub page

Replaces jMAVSim display-only mode references in the SIH page with Hawkeye,
which is purpose-built for this role and actively maintained. The 3D
visualization section now covers the hawkeye command, the port alignment
with SIH (UDP 19410), and links out to the full Hawkeye documentation.

Adds a short sim_hawkeye/index.md stub covering what Hawkeye is, install
on macOS and Linux, and basic SIH usage. Everything else (multi-vehicle,
ULog replay, HUD modes, CLI reference) lives at px4.github.io/Hawkeye
and is linked from the stub, so PX4 docs don't carry the maintenance
burden of two parallel sources.

Also updates the port reference table: UDP 19410 is now labeled
"Hawkeye visualizer" instead of "jMAVSim display-only", and adds the
page to SUMMARY.md nested under SIH Simulation.

* docs(update): subedit

---------

Co-authored-by: Hamish Willee <hamishwillee@gmail.com>

docs/en/sim_hawkeye/index.md

@@ -0,0 +1,61 @@
+# Hawkeye Visualizer
+
+[Hawkeye](https://px4.github.io/Hawkeye/) is a real-time 3D flight _visualizer_ for PX4.
+
+Hawkeye is the natural pair for [SIH](../sim_sih/index.md) — SIH runs the physics of an aircraft simulation and outputs MAVLink [HIL_STATE_QUATERNION](https://mavlink.io/en/messages/common.html#HIL_STATE_QUATERNION) messages, Hawkeye uses these to show you what's happening.
+
+Hawkeye has zero runtime dependencies, supports up to 16 vehicles simultaneously, and can replay PX4 ULog (`.ulg`) flight logs with transport controls, markers, and multi-drone correlation analysis.
+
+## Install
+
+### macOS (Homebrew)
+
+```sh
+brew tap PX4/px4
+brew install PX4/px4/hawkeye
+```
+
+### Linux (Debian/Ubuntu)
+
+Download the `.deb` from the [Hawkeye releases page](https://github.com/PX4/Hawkeye/releases/latest):
+
+```sh
+sudo dpkg -i hawkeye-*.deb
+```
+
+### Windows and source builds
+
+For Ubuntu 24.04 or later in WSL2 you can install the packages in the same way:
+
+```sh
+sudo dpkg -i hawkeye-*.deb
+```
+
+For other versions of Ubuntu (or native Windows builds) you may need to [Build from source](https://px4.github.io/Hawkeye/developer/build) (Hawkeye docs).
+
+## Usage with SIH
+
+Start PX4 SIH, then launch Hawkeye in a separate terminal:
+
+```sh
+# Terminal 1
+make px4_sitl sihsim_quadx
+
+# Terminal 2
+hawkeye
+```
+
+Hawkeye listens on UDP port 19410 — the same port SIH sends [HIL_STATE_QUATERNION](https://mavlink.io/en/messages/common.html#HIL_STATE_QUATERNION) on — so no configuration is needed.
+The vehicle appears in the Hawkeye window as soon as SIH starts streaming.
+
+For fixed-wing or tailsitter simulation, Hawkeye auto-detects the vehicle type from MAVLink `HEARTBEAT` and loads the matching 3D model.
+
+## Full documentation
+
+Complete documentation — including multi-vehicle SITL, ULog replay, HUD modes, camera controls, and correlation analysis — lives at **[px4.github.io/Hawkeye](https://px4.github.io/Hawkeye/)**.
+
+- [First SITL run](https://px4.github.io/Hawkeye/first-sitl) — the shortest path from install to seeing a vehicle move
+- [Multi-Drone Replay](https://px4.github.io/Hawkeye/multi_drone) — compare multiple flights with deconfliction and correlation
+- [Live SITL Integration](https://px4.github.io/Hawkeye/sitl) — single-vehicle and multi-instance swarm workflows
+- [Command-Line Reference](https://px4.github.io/Hawkeye/cli) — every CLI flag with examples
+- [Source code](https://github.com/PX4/Hawkeye)