j154 (default-off): the DERIVED bounded hold TR_TFIL_HOLD_MAX_TICKS + panic release

Budget derived from the server source (tank-royale 0.35.5): calcGunHeat(p) =
1 + p/5, coolDown 0.1/tick, fire only at heat == 0, calcBulletDamage(3.0) = 16
-> two max-power shots are 16 ticks apart and 32 damage is the most the enemy
can land in that window (brute force over the 0.1 power grid: 8/11/16/24/32
ticks -> 16/18/32/32/48). 16 = CommitTicks + 1, the first window that admits
the enemy's second shot.

Knob defaults to 0 = today's behaviour byte-for-byte (checked over 20026
ticks). Hold is taken only on a replan tick with an empty safe set, at most N
ticks per streak, released the tick a safe tile exists, counter reset on the
pick. PANIC RELEASE: a tracked bullet whose closest approach is within its core
at t* in [0, min(N,16)] overrides the hold immediately. The gun is untouched.

Also fixes a stray '&' that stopped test_tfil_commit_env.nim from compiling at
all, and enforces the 'a hold never interrupts a live commitment' invariant
j153 documented but did not implement. Registers TR_TFIL_HOLD_MAX_TICKS in
env_report + knownEnvNames + .env.example.

No battle, no A/B run.

ModularBot_garage/src/env_report.nim

@@ -317,6 +317,8 @@ proc printEffectiveValues(ctx: EnvReportContext) =
        sourceOf("TR_TFIL_ARRIVE_TICKS"))
   emit("TR_TFIL_HOLD_WHEN_TRAPPED", onOff(the_floor_is_lava.TfilHoldWhenTrapped),
        sourceOfPresence("TR_TFIL_HOLD_WHEN_TRAPPED"))
+  emit("TR_TFIL_HOLD_MAX_TICKS", $the_floor_is_lava.TfilHoldMaxTicks,
+       sourceOf("TR_TFIL_HOLD_MAX_TICKS"))
   emit("TR_TFIL_WALL_HOTNESS", $the_floor_is_lava_ring.WallHotness,
        sourceOf("TR_TFIL_WALL_HOTNESS"))
   emit("TR_TFIL_WALL_RADIANCE", $the_floor_is_lava.WallRadiance,
@@ -662,7 +664,7 @@ proc knownEnvNames*(): seq[string] =
     "TR_TFIL_RANGE_LO", "TR_TFIL_RANGE_HI", "TR_TFIL_RANGE_TEMP",
     "TR_TFIL_RANGE_K", "TR_TFIL_CORRIDOR_HEAT", "TR_TFIL_WALL_HOTNESS",
     "TR_TFIL_CORRIDOR_TICKS", "TR_TFIL_ARRIVE_TICKS",
-    "TR_TFIL_HOLD_WHEN_TRAPPED",
+    "TR_TFIL_HOLD_WHEN_TRAPPED", "TR_TFIL_HOLD_MAX_TICKS",
     "TR_TFIL_DANGER_THRESHOLD", "TR_TFIL_DIAG",
     "TR_TFIL_GEO_MODE", "TR_TFIL_GEO_TAU",
     "TR_TFIL_WALL_RADIANCE", "TR_TFIL_BULLET_CORE", "TR_TFIL_BULLET_AURA",