feat(SNNBot): adaptive fire power with lead scaling and velocity transition suppression

- P3 at err<0.5°, P1 at err<2.0° (was fixed P2); no fire at err>=2.0°
- Scale grid lead offset by bullet speed ratio (sin(θ) ∝ 1/v_bullet)
- ENERGY_GUARD 5→15 to survive Walls' sustained fire
- Suppress fire when |vPerp delta| > 2.0 (enemy changing direction)
- Store lastBulletSpeed = 20-3*chosenPower for correct EVALUATE travel time

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

SNNBot_garage/src/SNNBot.nim

@@ -71,12 +71,14 @@ const
   BETA     = 1.0         # surrogate steepness (unitless; potentials are unitless)
   NOISE_AMP = 0.3        # exploration noise amplitude
   # ponytail: uniform exploration noise; upgrade to annealed Gaussian if convergence needs tuning
-  ENERGY_GUARD  = 5.0    # P1 costs 1/shot, be aggressive
+  ENERGY_GUARD  = 15.0   # keep buffer; Walls hits us while we shoot
   P3_SPEED      = 11.0   # bullet speed for P3 (20 - 3*3); used for exemplar learning
   P1_SPEED      = 17.0   # bullet speed for P1 (20 - 3*1)
   P2_SPEED      = 14.0   # bullet speed for P2 (20 - 3*2)
+  GRID_BULLET_SPEED = 14.0  # reference speed the grid learns at (power 2)
   COLD_K        = 3      # exemplars needed before leaving cold start
   PATIENCE_TICKS = 5     # P1 is forgiving, less patience needed
+  VPERP_TRANSITION = 2.0 # suppress fire when |vPerp change| > this (enemy changing direction)
 
 # ── SNN types ─────────────────────────────────────────────────────────────────
 
@@ -246,6 +248,7 @@ type
     velSpeed:        float64            # speed (units/tick) from last scan delta
     lastDecideGunDir: float             # gun heading captured at DECIDE time for EVALUATE
     lastVPerp:       float              # DECIDE-time vPerp, reused in EVALUATE
+    prevTickVPerp:   float              # vPerp from previous tick (transition detection)
     lastAbsBearing:  float             # absolute bearing to enemy captured at DECIDE time
     roundTick:        int                # ticks elapsed in current round (reset each round)
     bulletsFired:     int                # count of bullets fired this round
@@ -326,6 +329,7 @@ method onRoundStarted*(bot: SNNBot, e: RoundStartedEvent) =
   bot.lastEnemyX   = 0.0
   bot.lastEnemyY   = 0.0
   bot.lastAbsBearing = 0.0
+  bot.prevTickVPerp = 0.0
   bot.lastDecideGunDir = 0.0
   bot.targetAngle  = 0.0
   setTargetSpeed(0.0)
@@ -381,19 +385,25 @@ method run*(bot: SNNBot) =
         while relVelDir >= 180.0: relVelDir -= 360.0
         while relVelDir < -180.0: relVelDir += 360.0
         let vPerp = bot.velSpeed * sin(degToRad(relVelDir))
-        let aimOffset = bot.res.forward(vPerp, bot.enemyDist)
+        let gridOffset = bot.res.forward(vPerp, bot.enemyDist)
         bot.lastVPerp        = vPerp
         bot.lastDecideGunDir = gunDir
         bot.lastAbsBearing   = absBearing
         let rate = if bot.bulletsFired > 0: float(bot.bulletsHit) / float(bot.bulletsFired) * 100.0 else: 0.0
-        if aimOffset <= -999.0:
+        if gridOffset <= -999.0:
           bot.targetAngle = absBearing
           echo "RES tick=" & $bot.tick & " pwr=" & formatFloat(bot.currentFirePower, ffDecimal, 1) & " hitEMA=" & formatFloat(bot.hitRateEMA * 100.0, ffDecimal, 0) & "% cold-start aim=" & formatFloat(absBearing, ffDecimal, 1) & " fired=" & $bot.bulletsFired & " hit=" & $bot.bulletsHit & " rate=" & formatFloat(rate, ffDecimal, 1) & "% energy=" & formatFloat(getEnergy(), ffDecimal, 0) & " cells=" & $bot.res.totalCount
           diagLog("DECIDE tick=" & $bot.tick & " offset=cold-start cells=" & $bot.res.totalCount)
         else:
+          # Scale grid offset (learned at GRID_BULLET_SPEED) to chosen fire power speed.
+          # sin(leadAngle) ∝ 1/bulletSpeed, so scale sin of the offset.
+          let chosenSpeed = 20.0 - 3.0 * bot.currentFirePower
+          let sinGrid   = sin(degToRad(gridOffset))
+          let sinScaled = clamp(sinGrid * GRID_BULLET_SPEED / chosenSpeed, -1.0, 1.0)
+          let aimOffset = radToDeg(arcsin(sinScaled))
           bot.targetAngle = (absBearing + aimOffset + 360.0) mod 360.0
           echo "RES tick=" & $bot.tick & " pwr=" & formatFloat(bot.currentFirePower, ffDecimal, 1) & " hitEMA=" & formatFloat(bot.hitRateEMA * 100.0, ffDecimal, 0) & "% offset=" & formatFloat(aimOffset, ffDecimal, 1) & " aim=" & formatFloat(bot.targetAngle, ffDecimal, 1) & " fired=" & $bot.bulletsFired & " hit=" & $bot.bulletsHit & " rate=" & formatFloat(rate, ffDecimal, 1) & "% energy=" & formatFloat(getEnergy(), ffDecimal, 0) & " cells=" & $bot.res.totalCount
-          diagLog("DECIDE tick=" & $bot.tick & " offset=" & formatFloat(aimOffset, ffDecimal, 2) & "° cells=" & $bot.res.totalCount)
+          diagLog("DECIDE tick=" & $bot.tick & " offset=" & formatFloat(aimOffset, ffDecimal, 2) & "° gridOffset=" & formatFloat(gridOffset, ffDecimal, 2) & "° cells=" & $bot.res.totalCount)
       else:
         let inputs = encodeInputFull(absBearing, bot.velDirDeg, bot.velSpeed, bot.hasLastPos)
         # Multi-tick inference: accumulate sin/cos and spike counts over N_INFER ticks
@@ -426,14 +436,33 @@ method run*(bot: SNNBot) =
       aimTo(bot.targetAngle, gunDir)
       let err = abs(normalizeRelativeAngle(bot.targetAngle - gunDir))
 
-      # Fire gate: gun must be aimed and settled before firing
+      # Velocity transition detection: recompute current vPerp
+      var curVPerp = bot.lastVPerp
+      if bot.hasLastPos:
+        var relVelDir2 = bot.velDirDeg - bot.enemyBearing
+        while relVelDir2 >= 180.0: relVelDir2 -= 360.0
+        while relVelDir2 < -180.0: relVelDir2 += 360.0
+        curVPerp = bot.velSpeed * sin(degToRad(relVelDir2))
+      let vPerpTransition = abs(curVPerp - bot.prevTickVPerp) > VPERP_TRANSITION
+      bot.prevTickVPerp = curVPerp
+
+      # Fire gate: gun aimed, enough energy, not in cold-start, enemy not changing direction
       let energy = getEnergy()
-      let readyToFire = err < 2.0 and energy >= ENERGY_GUARD and bot.roundTick >= PATIENCE_TICKS
       let leadOffset = normalizeRelativeAngle(bot.targetAngle - bot.lastAbsBearing)
-      appendLog(aimDebugLog, fmt"TICK t={bot.roundTick} err={err:.2f} offset={leadOffset:.2f} vPerp={bot.lastVPerp:.2f} dist={bot.enemyDist:.1f} fired={readyToFire}")
+      appendLog(aimDebugLog, fmt"TICK t={bot.roundTick} err={err:.2f} offset={leadOffset:.2f} vPerp={bot.lastVPerp:.2f} dist={bot.enemyDist:.1f} transition={vPerpTransition}")
+
+      # Adaptive fire power: high confidence = P3 (damage), low = P1 (cheap miss)
+      let chosenPower =
+        if err < 0.5: 3.0
+        elif err < 2.0: 1.0
+        else: 0.0
+      bot.currentFirePower = if chosenPower > 0.0: chosenPower else: bot.currentFirePower
+
+      let readyToFire = chosenPower > 0.0 and energy >= ENERGY_GUARD and
+                        bot.roundTick >= PATIENCE_TICKS and not vPerpTransition
       if readyToFire:
-        bot.lastBulletSpeed = P2_SPEED
+        bot.lastBulletSpeed = 20.0 - 3.0 * chosenPower
-        discard setFire(2.0)
+        discard setFire(chosenPower)
         bot.phase = EVALUATE
       else:
         discard setFire(0.0)