Add drone telemetry Lua decoder examples and test data generator

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

.gitignore

@@ -3,3 +3,6 @@
 # Compiled binaries in tools/
 tools/test_plot_c
 tools/test_text_c
+
+# Python
+__pycache__/

examples/drone_plot.lua

@@ -0,0 +1,16 @@
+return {
+    decode = function(frame)
+        if #frame == 0 then return nil end
+
+        local gyro_str = frame:match("Gyro:([%d%.%-]+),([%d%.%-]+),([%d%.%-]+)")
+        if not gyro_str then return nil end
+
+        local gz, gy, gx = frame:match("Gyro:([%d%.%-]+),([%d%.%-]+),([%d%.%-]+)")
+        return {
+            kind = "plot",
+            channels = { { tonumber(gz) }, { tonumber(gy) }, { tonumber(gx) } },
+            sample_type = "F64",
+            format = "Block",
+        }
+    end,
+}

examples/drone_text.lua

@@ -0,0 +1,33 @@
+local LABELS = {
+    AHRS = "Quaternion",
+    YPR  = "Yaw/Pitch/Roll",
+    Gyro = "Gyro (deg/s)",
+    RC   = "RC Channels",
+    M    = "Motors",
+    L    = "L",
+    F    = "F",
+    C    = "C",
+}
+
+return {
+    decode = function(frame)
+        if #frame == 0 then return nil end
+
+        local lines = {}
+        for segment in frame:gmatch("[^|]+") do
+            local colon = segment:find(":")
+            if colon then
+                local key = segment:sub(1, colon - 1)
+                local val = segment:sub(colon + 1)
+                local label = LABELS[key] or key
+                lines[#lines + 1] = string.format("%-18s %s", label .. ":", val)
+            end
+        end
+        lines[#lines + 1] = string.rep("-", 40)
+
+        return {
+            kind = "text",
+            data = table.concat(lines, "\n"),
+        }
+    end,
+}

tools/test_drone.py

@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+"""Generate fake drone telemetry data for testing xserial Lua decoder."""
+
+import argparse
+import math
+import random
+import socket
+import time
+
+
+def generate_line(t: float) -> str:
+    """Generate one telemetry line with simulated sensor values."""
+    # Quaternion (w, x, y, z) — gently rotating
+    angle = t * 0.5
+    qw = math.cos(angle)
+    qx = math.sin(angle) * 0.1
+    qy = math.sin(angle) * 0.05
+    qz = math.sin(angle) * 0.02
+
+    # Yaw/Pitch/Roll — sine wave simulation
+    yaw = math.degrees(math.sin(t * 0.3)) * 30
+    pitch = math.degrees(math.sin(t * 0.5)) * 15
+    roll = math.degrees(math.sin(t * 0.7)) * 10
+
+    # Gyro (deg/s)
+    gz = math.sin(t * 0.3) * 50 + random.uniform(-2, 2)
+    gy = math.sin(t * 0.5) * 30 + random.uniform(-2, 2)
+    gx = math.sin(t * 0.7) * 20 + random.uniform(-2, 2)
+
+    # RC channels (1000-2000 us)
+    rc_r = int(1500 + math.sin(t * 0.3) * 200)
+    rc_p = int(1500 + math.sin(t * 0.5) * 150)
+    rc_t = int(1000 + (math.sin(t * 0.1) + 1) * 500)  # throttle 1000-2000
+    rc_y = int(1500 + math.sin(t * 0.3) * 100)
+
+    # Motors (1000-2000)
+    base = 1200 + int((math.sin(t * 0.1) + 1) * 400)
+    m1 = base + random.randint(-20, 20)
+    m2 = base + random.randint(-20, 20)
+    m3 = base + random.randint(-20, 20)
+    m4 = base + random.randint(-20, 20)
+
+    return (
+        f"AHRS q:{qw:.4f},{qx:.4f},{qy:.4f},{qz:.4f}|"
+        f"YPR:{yaw:.2f},{pitch:.2f},{roll:.2f}|"
+        f"Gyro:{gz:.2f},{gy:.2f},{gx:.2f}|"
+        f"RC:{rc_r},{rc_p},{rc_t},{rc_y}|"
+        f"M:{m1},{m2},{m3},{m4}|"
+        f"L:0 F:1 C:0\n"
+    )
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Drone telemetry test data generator")
+    parser.add_argument("--host", default="127.0.0.1", help="TCP host")
+    parser.add_argument("--port", type=int, default=8092, help="TCP port")
+    parser.add_argument("--rate", type=float, default=10, help="Lines per second")
+    parser.add_argument("--duration", type=float, default=0, help="Seconds to run (0 = forever)")
+    args = parser.parse_args()
+
+    interval = 1.0 / args.rate
+    print(f"Sending drone telemetry to {args.host}:{args.port} at {args.rate} Hz")
+
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server:
+        server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        server.bind((args.host, args.port))
+        server.listen(1)
+        print(f"Listening on {args.host}:{args.port}, waiting for connections...")
+
+        while True:
+            sock, addr = server.accept()
+            print(f"Client connected from {addr}")
+
+            t0 = time.time()
+            seq = 0
+
+            try:
+                while True:
+                    t = time.time() - t0
+                    line = generate_line(t)
+                    try:
+                        sock.sendall(line.encode())
+                    except (BrokenPipeError, ConnectionResetError):
+                        break
+                    seq += 1
+
+                    if args.duration > 0 and t >= args.duration:
+                        break
+
+                    elapsed = time.time() - t0
+                    target = (seq + 1) * interval
+                    sleep_time = target - elapsed
+                    if sleep_time > 0:
+                        time.sleep(sleep_time)
+            except (BrokenPipeError, ConnectionResetError):
+                pass
+
+            print(f"Client disconnected. Sent {seq} lines. Waiting for new connection...")
+
+
+if __name__ == "__main__":
+    main()