J1: Extra Attack now fires in turn-based combat

The class-identity audit (98ba416) wired Extra Attack via the new
resolvePlayerSwings helper, but only SimulateCombat (auto-resolve)
called it. The turn-based engine — every !fight/!attack and every
elite/boss gate the sim drives via autoResolveCombat — still called
single-swing resolvePlayerAttack, so Fighter L11+ got 1 swing/turn at
the gates instead of 3. The audit close-out was correct in spirit but
half-applied.

J1 baseline matrix surfaced it: Fighter L12 cleared 100% of T2 forest
but 2% of T3 manor and 7% of T4 underdark, with %boss_reached at 100%
across the board. The wall was the boss-room damage exchange, not
mid-zone attrition. Trace dump on a sample fight: Fighter dealt 79
dmg in 14 rounds (7 hits / 9 swings) — exactly one swing per round —
versus 167 enemy dmg. With multi-swing wired in, the same fight ends
in 7 rounds with the boss dead, Fighter at 87/168 HP, 16 hits in 19
swings.

n=100 matrix after the fix:
  Fighter L12 manor:     2% → 100% clr
  Fighter L12 underdark: 7% → 98%  clr
  Fighter L12 forest:    94% → 100% (no leader regression)
Mage cells unchanged (J2 territory). Rogue cells within noise.

Sim infra changes that landed alongside (needed to read the J1
signal):

* expedition_sim auto-arms class-default defensive abilities
  (Second Wind / Healing Word) via the new simAutoArmEnabled toggle
  + trySimAutoArm helper, hooked before applyArmedAbility in both
  combat builders. Production code paths untouched (toggle stays
  off). Without this the sim simulated a player who never types
  !arm, which under-counts class survival.
* SimResult.Combats captures per-fight turn-log summaries (rounds,
  hits/misses, damage by side, AC values inferred from RollAgainst)
  so future J-phase questions can dig into the engine without
  re-running the matrix.
* sim_results/run_matrix.sh fans the matrix across (class,level,zone)
  cells via xargs -P (one process per cell — each owns its global
  sqlite handle). ~6× wall-clock speedup on a 14-core box; n=100
  matrix runs in ~3min.
* sim_results/summarize.sh gains p50_yld_clr + %boss_reached columns
  so future sweeps don't conflate "reaches boss" with "clears zone".

Baselines:
  sim_results/baseline_j0_n100.jsonl       — pre-fix (1350 rows)
  sim_results/baseline_j1_extra_attack.jsonl — post-fix (4500 rows)

Phase J state: J0 baseline locked, J1 done. T5 dragons_lair still
0% clear universally (J3). Mage T2+ wall still real (J2).

sim_results/run_matrix.sh

@@ -0,0 +1,80 @@
+#!/usr/bin/env bash
+# Parallel driver for cmd/expedition-sim matrix sweeps.
+#
+# Spawns one expedition-sim process per (class, level, zone) cell, so each
+# worker owns its own global sqlite handle (NewSimRunner closes+reinits the
+# package-level db.Get() — workers in the same process would clobber each
+# other). All worker stdouts are concatenated into a single JSONL.
+#
+# Usage:
+#   run_matrix.sh OUTFILE RUNS CLASSES LEVELS ZONES [PARALLEL]
+#
+# Example (1350 rows, 14-way parallel):
+#   run_matrix.sh baseline_j0.jsonl 30 \
+#     fighter,mage,rogue 3,7,12 \
+#     goblin_warrens,forest_shadows,manor_blackspire,underdark,dragons_lair
+set -euo pipefail
+
+outfile=${1:?outfile required}
+runs=${2:?runs required}
+classes=${3:?classes required}
+levels=${4:?levels required}
+zones=${5:?zones required}
+parallel=${6:-$(nproc)}
+
+repo=$(cd "$(dirname "$0")/.." && pwd)
+bin=$repo/expedition-sim
+[[ -x "$bin" ]] || { echo "missing $bin — run 'go build ./cmd/expedition-sim' first" >&2; exit 1; }
+
+cd "$repo/sim_results"
+tmpdir=$(mktemp -d -t simrun-XXXXXX)
+trap 'rm -rf "$tmpdir"' EXIT
+
+errfile=${outfile%.jsonl}.err
+: > "$outfile"
+: > "$errfile"
+
+# Enumerate cells one per line: "class level zone".
+cells=$tmpdir/cells.txt
+IFS=, read -ra cls <<< "$classes"
+IFS=, read -ra lvs <<< "$levels"
+IFS=, read -ra zns <<< "$zones"
+for c in "${cls[@]}"; do
+  for l in "${lvs[@]}"; do
+    for z in "${zns[@]}"; do
+      printf "%s\t%s\t%s\n" "$c" "$l" "$z"
+    done
+  done
+done > "$cells"
+
+ncells=$(wc -l < "$cells")
+echo "matrix: $ncells cells × $runs runs = $((ncells * runs)) rows, $parallel workers" >&2
+
+# Fan out: one process per cell. Per-cell stdout goes to its own shard,
+# stderr is collected to the shared errfile.
+worker() {
+  local class=$1 level=$2 zone=$3
+  local shard=$tmpdir/$class-$level-$zone.jsonl
+  "$bin" -matrix \
+    -classes "$class" -levels "$level" -zones "$zone" \
+    -runs "$runs" \
+    > "$shard" 2>> "$errfile"
+}
+export -f worker
+export bin tmpdir runs errfile
+
+xargs -P "$parallel" -L 1 -a "$cells" bash -c 'worker "$@"' _
+
+# Stitch shards in deterministic order (zone, class, level — matches
+# summarize.sh's sort_by) so diff-friendliness survives parallel arrival.
+for c in "${cls[@]}"; do
+  for l in "${lvs[@]}"; do
+    for z in "${zns[@]}"; do
+      shard=$tmpdir/$c-$l-$z.jsonl
+      [[ -f "$shard" ]] && cat "$shard" >> "$outfile"
+    done
+  done
+done
+
+rows=$(wc -l < "$outfile")
+echo "wrote $rows rows → $outfile (errors in $errfile)" >&2