Add WireShark dissector (#2140)

## Description

<img width="1918" height="1030" alt="image"
src="https://github.com/user-attachments/assets/5af1a5ee-012d-461d-9162-2d4de6ad0c62"
/>

A wireshark dissector can be handy for quickly visualizing time sync
messages. See the docs for how to use this!

Full disclosure -- this dissector was generated by Claude 4.5, and I
spot-checked all the numbers for correctness. This seems like idiomatic
Lua to me, but I don't know Lua at all. I don't see a nice QOL thing
nobody else will use as being a tech debt concern.

## Meta

Merge checklist:
- [x] Pull Request title is [short, imperative
summary](https://cbea.ms/git-commit/) of proposed changes
- [x] The description documents the _what_ and _why_
- [ ] If this PR changes behavior or adds a feature, user documentation
is updated
- [ ] If this PR touches photon-serde, all messages have been
regenerated and hashes have not changed unexpectedly
- [ ] If this PR touches configuration, this is backwards compatible
with settings back to v2025.3.2
- [ ] If this PR touches pipeline settings or anything related to data
exchange, the frontend typing is updated
- [ ] If this PR addresses a bug, a regression test for it is added

docs/source/docs/contributing/design-descriptions/time-sync.md

@@ -109,3 +109,13 @@ Clients may publish statistics to NetworkTables. If they do, they shall publish
 | rtt2_us | Integer | The time in us from last complete (ping transmission to pong reception) |
 
 PhotonVision has chosen to publish to the sub-table `/photonvision/.timesync/{DEVICE_HOSTNAME}`. Future implementations of this protocol may decide to implement this as a structured data type.
+
+## Wireshark Dissector
+
+![](images/wireshark.jpg)
+
+A [WireShark dissector](https://raw.githubusercontent.com/PhotonVision/photonvision/refs/heads/main/devTools/photon.lua) created for Wireshark ~=4.6 can be used to inspect Time Syncronization messages. Copy the dissector to your Wireshark plugin directory (for me, that's `C:\Users\Me\AppData\Roaming\Wireshark\plugins`), and open the capture. Because TSP uses UDP Unicast, data must be collected on the coprocessor or robot processor using a command similar to:
+
+```
+sudo tcpdump -i any port 5810 -w tsp_capture.pcap
+```