Add demos for OutageNet, YardGate, and AgriMesh in README; update Pod…

[Ankush523]

Summary

• Adds catalogue demo.gif assets (960×540, iOS + Android side-by-side) for the three vertical demos recorded on devices:
  • OutageNet — Android field unit + iOS command post
  • YardGate — iOS + Android yard check-in / gate roles
  • AgriMesh — Android office edge + iOS field collector
• Embeds those GIFs in the root README (same pattern as Order Up, Stock Sync, Cowrite, Tic Tac Together) and in each app’s README.
• Event Floor remains a placeholder in the root README (demo-staff.gif / demo-gate.gif not included in this PR).

Test plan

• Open root README.md on GitHub and confirm OutageNet, YardGate, and AgriMesh GIFs render.
• Spot-check apps/outagenet/demo.gif, apps/yardgate/demo.gif, and apps/agrimesh/demo.gif locally.
• No runtime or CI logic changes beyond minor iOS Podfile.lock / project housekeeping in OutageNet and YardGate.

Notes

• GIFs were produced from device screen recordings (trimmed, 8 fps) for README catalogue use.
• Event Floor demo assets can follow in a separate PR when recordings are ready.