fix(adversaries): repair four of the five sparring bots

The user suspected these were bugged. They were, and the verdicts are not
uniform - three genuinely broken, one merely sloppy, one fine:

- WaveSurfer: GENUINELY BUGGED, worst of the five. (a) The enemy velocity
  decomposition was sin/cos SWAPPED - enemyVx used sin and enemyVy used cos,
  while Tank Royale is 0 deg = East, CCW+, so it must be cos for X and sin for
  Y. Its linear-prediction gun was aiming at a reflected position. (b) The wall
  escape flipped strafeDir on EVERY tick the bot was inside the wall margin,
  so instead of turning away it flip-flopped in place: measured standing still
  (speed < 0.5) for 96.2% of ticks with a longest continuous standstill of 1398
  ticks. Fixed with a hysteretic wall-escape selection plus a corner escape,
  dead enemyLastDir removed, and per-round state reset.
  AFTER, measured through the booter: rest 12.3%, mean speed 6.69, full speed
  79.7%, longest zero run 18, perpendicular 0.845 / radial 0.012 - it now
  actually strafes. Gun sanity: lead error 1.0 px vs 106 px for head-on on a
  constant-velocity target; lead gun 45.8% hits vs 29.3% for head-on.
- PatternMover: GENUINELY BUGGED. Real deadlock - it decremented its step
  counter by the REQUESTED amount while issuing setTargetSpeed(8), so against a
  wall the counter never reached 0, advanceStep never ran and it was stuck
  forever (309-tick standstill). Now counts down by ACTUAL distance/turn with a
  STALL_LIMIT watchdog and steers toward the arena centre. Standstill 309 -> 19
  ticks; full-speed ticks 10.0% -> 28.4%.
- OscillatorBot: GENUINELY BUGGED, milder. No wall handling at all, so it
  ground along walls 53.4% of ticks and could pin in a corner. Added wall
  steering that preserves the fixed 25-tick reversal cadence. Wall-band 53.4%
  -> 18.6%, mean wall distance 72 -> 119.
- RandomMover: merely sloppy, not broken. Its turn intent saturated against the
  speed-dependent limit (18.4% of moving ticks clamped) and the fire gate was a
  very loose 10 deg. Now clamps to calcMaxTurnRate and fires within 3 deg.
  Saturation 18.4% -> 3.9%.
- SittingDuck: FINE. Speed 0 for 100% of ticks, zero shots. Left untouched -
  it is a duck by design.

Adds test_wavesurfer_velocity.nim, a direct assertion that the decomposition is
cos/sin and explicitly NOT the swapped form (7 cases).

KNOWN ISSUE, not fixed: RandomMover/PatternMover/WaveSurfer import
tankroyale_botapi 1.0.1 and intermittently SIGSEGV in
tankroyale_botapi/event_queue.nim:89 addEvent, freezing the bot for the rest of
the battle. It reproduces on old and new code and never occurs for SittingDuck/
OscillatorBot, which import robocode_tankroyale_botapi 1.0.7. Migrating the
three to 1.0.7 would likely fix it and is worth doing - it is a real
reliability risk for these as sparring partners.

common_libs/test_framework/adversaries/RandomMover/src/RandomMover.nim

@@ -13,7 +13,11 @@ type RandomMover = ref object of Bot
 
 proc newDirection(bot: RandomMover) =
   bot.currentSpeed      = rand(-8.0..8.0)
-  bot.currentTurn       = rand(-10.0..10.0)
+  # The server caps body turn at calcMaxTurnRate(speed) = 10 - 0.75*|speed|
+  # (~4 deg/tick at full speed); keep the random intent inside that limit so it
+  # is not silently saturated by the server.
+  let maxTurn           = calcMaxTurnRate(bot.currentSpeed)
+  bot.currentTurn       = rand(-maxTurn..maxTurn)
   bot.ticksUntilChange  = rand(10..20)
 
 method onRoundStarted*(bot: RandomMover, e: RoundStartedEvent) =
@@ -27,7 +31,7 @@ method onScannedBot*(bot: RandomMover, e: ScannedBotEvent) =
   let bearing  = directionTo(getX(), getY(), e.x, e.y)
   let gunDelta = normalizeRelativeAngle(bearing - getGunDirection())
   setGunTurnRate(gunDelta.clamp(-MAX_GUN_TURN_RATE, MAX_GUN_TURN_RATE))
-  if abs(gunDelta) < 10.0 and getGunHeat() <= 0.0:
+  if abs(gunDelta) < 3.0 and getGunHeat() <= 0.0:
     discard setFire(1.0)
 
 method run*(bot: RandomMover) =