feat: add xmSimulator to the family — icon (Ψ) + umbrella registration

.gitmodules

@@ -22,3 +22,7 @@
 	path = components/messaging
 	url = https://github.com/rxdu/xmMessaging.git
 	branch = main
+[submodule "components/simulator"]
+	path = components/simulator
+	url = https://github.com/rxdu/xmSimulator.git
+	branch = main

CMakeLists.txt

@@ -40,6 +40,7 @@ option(XMOTION_WITH_DRIVER    "Build xmDriver (host hardware drivers)"   ON)
 option(XMOTION_WITH_NAVIGATION "Build xmNavigation (motion algorithms)"    ON)
 option(XMOTION_WITH_VIEWER "Build xmViewer (visualization)"        OFF)
 option(XMOTION_WITH_MESSAGING "Build xmMessaging (communication layer)" OFF)
+option(XMOTION_WITH_SIMULATOR "Build xmSimulator (physics simulation)"  OFF)
 option(BUILD_TESTING      "Build component tests"                OFF)
 
 # -- Helper: add a component submodule if it is present ---------------------
@@ -78,7 +79,13 @@ if(XMOTION_WITH_MESSAGING)
   xmotion_add_component(xmMessaging components/messaging)
 endif()
 
+# xmSimulator: MuJoCo-backed physics simulation (world · sensors · dynamics).
+# Default OFF — it pulls the MuJoCo dependency; opt-in for apps that simulate.
+if(XMOTION_WITH_SIMULATOR)
+  xmotion_add_component(xmSimulator components/simulator)
+endif()
+
 message(STATUS "xMotion ${PROJECT_VERSION}: configured "
                "(TELEMETRY=${XMOTION_WITH_TELEMETRY} DRIVER=${XMOTION_WITH_DRIVER} "
                "NAVIGATION=${XMOTION_WITH_NAVIGATION} VIEWER=${XMOTION_WITH_VIEWER} "
-               "MESSAGING=${XMOTION_WITH_MESSAGING})")
+               "MESSAGING=${XMOTION_WITH_MESSAGING} SIMULATOR=${XMOTION_WITH_SIMULATOR})")

README.md

@@ -13,7 +13,8 @@
 <img src="branding/icons/xmdriver.svg" width="48" alt="xmDriver">&nbsp;
 <img src="branding/icons/xmnavigation.svg" width="48" alt="xmNavigation">&nbsp;
 <img src="branding/icons/xmmessaging.svg" width="48" alt="xmMessaging">&nbsp;
-<img src="branding/icons/xmviewer.svg" width="48" alt="xmViewer">
+<img src="branding/icons/xmviewer.svg" width="48" alt="xmViewer">&nbsp;
+<img src="branding/icons/xmsimulator.svg" width="48" alt="xmSimulator">
 
 </div>
 
@@ -33,10 +34,11 @@ This repository is the **umbrella**: a thin CMake superbuild that assembles the
 | **∇** | xmNavigation | motion algorithms — planning · control · estimation · mapping&nbsp;·&nbsp;*centerpiece* | [rxdu/xmNavigation](https://github.com/rxdu/xmNavigation) |
 | **π** | xmMessaging | application communication — typed pub/sub · request/response · zero-copy transport | [rxdu/xmMessaging](https://github.com/rxdu/xmMessaging) |
 | **γ** | xmViewer | visualization | [rxdu/quickviz](https://github.com/rxdu/quickviz) |
+| **Ψ** | xmSimulator | physics simulation — MuJoCo world · sensors · dynamics | [rxdu/xmSimulator](https://github.com/rxdu/xmSimulator) |
 
 <sup>1</sup> *xmTelemetry — the production observability SDK and tooling — is privately maintained; available for production integrations.*
 
-Component names follow [ADR 0003](docs/adr/0003-naming-and-branding.md); the Greek letters (κ ζ Σ τ μ ∇ γ π) are retained as logos only — every repo, submodule path, and icon file now carries its functional name. Everything builds on **xmBase**; dependencies point downward only. Two pairs span the boundary: **xmBase/xmDriver** on the host, **xmFirmware/xmBoard** on the embedded target — with **xmNavigation** the motion-algorithms core.
+Component names follow [ADR 0003](docs/adr/0003-naming-and-branding.md); the Greek letters (κ ζ Σ τ μ ∇ γ π Ψ) are retained as logos only — every repo, submodule path, and icon file now carries its functional name. Everything builds on **xmBase**; dependencies point downward only. Two pairs span the boundary: **xmBase/xmDriver** on the host, **xmFirmware/xmBoard** on the embedded target — with **xmNavigation** the motion-algorithms core.
 
 ## Applications
 

branding/README.md

@@ -20,6 +20,7 @@ A cohesive icon set for the XMotion family. Each icon shares one visual language
     <td align="center"><img src="icons/xmfirmware.svg" width="84" alt="xmFirmware"></td>
     <td align="center"><img src="icons/xmboard.svg" width="84" alt="xmBoard"></td>
     <td align="center"><img src="icons/xmmessaging.svg" width="84" alt="xmMessaging"></td>
+    <td align="center"><img src="icons/xmsimulator.svg" width="84" alt="xmSimulator"></td>
   </tr>
   <tr>
     <td align="center"><b>xmBase</b><br>Σ</td>
@@ -30,6 +31,7 @@ A cohesive icon set for the XMotion family. Each icon shares one visual language
     <td align="center"><b>xmFirmware</b><br>ζ</td>
     <td align="center"><b>xmBoard</b><br>κ</td>
     <td align="center"><b>xmMessaging</b><br>π</td>
+    <td align="center"><b>xmSimulator</b><br>Ψ</td>
   </tr>
 </table>
 
@@ -43,6 +45,7 @@ A cohesive icon set for the XMotion family. Each icon shares one visual language
 | **xmFirmware** | `#46B358` green | ζ | a UART decode — logic-analyzer waveform + the decoded byte `0x5A` — firmware (Zephyr) |
 | **xmBoard** | `#E5604D` coral | κ | a PCB fan-out — a quad IC footprint, a structured 45° trace fan onto a via column, and short top/bottom escapes — electronics (KiCAD) |
 | **xmMessaging** | `#2E90FA` signal blue | π | a brokerless peer-to-peer mesh — nodes exchanging messages directly (the application communication layer) |
+| **xmSimulator** | `#B0C918` chartreuse | Ψ | an isometric quadruped robot standing on the ground — legged locomotion / physics simulation (MuJoCo) |
 
 ## The family mark — xmMotion
 

branding/preview/index.html

@@ -83,6 +83,7 @@ <h2>family strip</h2>
   { id:"xmfirmware",   name:"xmFirmware · ζ",    color:"#46B358" },
   { id:"xmboard",      name:"xmBoard · κ",       color:"#E5604D" },
   { id:"xmmessaging",  name:"xmMessaging · π",   color:"#2E90FA" },
+  { id:"xmsimulator",  name:"xmSimulator · Ψ",   color:"#B0C918" },
   { id:"xmmotion",     name:"xmMotion · robot",  color:"#EAEFF7" },
   { id:"xmmotion-mark",name:"xmMotion · Ξ",      color:"#EAEFF7" },
 ];