feat(print): Windows print agent — the cloud↔LAN bridge (Phase 3)

A standalone net10.0-windows console app (agent/Meezi.PrintAgent) installed on the
café cash PC. It pairs with a one-time code (POST /print-agent/claim), stores the
token in %APPDATA%, holds a SignalR connection to /hubs/print-agent (retries
forever, re-reports on reconnect), discovers installed printers via WMI (USB +
network, classified), and prints jobs it receives by writing raw ESC/POS bytes —
winspool RAW passthrough for installed printers, raw TCP for ip:port devices —
acking each job back. Not in the API solution or CI (own net10.0-windows build);
see agent/README.md for build/publish/pair. Builds clean; startup + pairing flow
smoke-tested.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

agent/README.md

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+# Meezi Print Agent (پرینت‌سرور میزی)
+
+A tiny Windows background app that lets the **cloud-hosted** Meezi reach printers on
+the café's **local network** (USB or Wi-Fi/Ethernet). The cloud can't open a
+connection to a `192.168.x.x` or USB printer directly — this agent runs on the cash
+PC (which *is* on that network), connects **outward** to Meezi over SignalR, reports
+the printers it can see, and prints the jobs the cloud sends it.
+
+```
+Cloud API ──SignalR(out)──► Print Agent (cash PC) ──► USB / LAN printers
+```
+
+## How it works
+1. In the dashboard: **Settings → Printers → Add print server** → you get a pairing code.
+2. Run the agent on the cash PC, enter the code once. It saves a token to
+   `%APPDATA%\MeeziPrintAgent\config.json` and connects.
+3. It reports every printer installed on that PC. Back in the dashboard you map
+   *receipt / kitchen / bar* to a printer from the dropdown — no IP typing.
+4. When Meezi prints, the bytes (ESC/POS) are relayed to the agent, which writes them
+   raw to the chosen printer (`winspool` for installed printers, raw TCP for
+   `ip:port` devices).
+
+## Build & run (dev)
+Requires the .NET 10 SDK on Windows.
+
+```sh
+# restore via the Nexus mirror (nuget.org is blocked on this network)
+dotnet restore agent/Meezi.PrintAgent/Meezi.PrintAgent.csproj -s https://mirror.soroushasadi.com/repository/nuget-group/
+dotnet run --project agent/Meezi.PrintAgent          # first run prompts to pair
+dotnet run --project agent/Meezi.PrintAgent -- pair  # re-pair later
+```
+
+## Publish a single .exe for cafés
+```sh
+dotnet publish agent/Meezi.PrintAgent -c Release -r win-x64 \
+  -p:PublishSingleFile=true --self-contained true -o dist/agent
+# → dist/agent/MeeziPrintAgent.exe
+```
+
+## Notes / roadmap
+- **Not part of the API solution or CI** — it targets `net10.0-windows` and builds on its own.
+- Console MVP today. Next: system-tray UI, run-at-login (Task Scheduler / service), auto-update, and an optional LAN scan for raw `ip:9100` printers that aren't installed in Windows.
+- The token is bearer-equivalent — keep `config.json` on a trusted machine. Revoke from the dashboard if a PC is lost.