feat: add shared integration test framework for garages (#126)

Implements:
- BattleResult type and JSON-lines parser (#127)
- TR server lifecycle manager (#128)
- Bot compiler using nim c (#129)
- runBattle() orchestrator (#130)
- Example test in OscillatorBot_garage (#131)
- Framework usage guide (#132)
- TestBattleRunner.java for external server (#133)
- BattleRunner process lifecycle (#134)

Fix: runner_process.nim was redefining TimeoutError locally; now
uses std/net.TimeoutError consistently with server_manager.nim.

common_libs/test_framework/battle_result.nim

@@ -0,0 +1,82 @@
+import std/[json, strutils, sequtils]
+
+type
+  BotRoundResult* = object
+    name*: string
+    score*: int
+    rank*: int
+    survived*: bool
+
+  RoundResult* = object
+    round*: int
+    results*: seq[BotRoundResult]
+
+  BotResult* = object
+    name*: string
+    totalScore*: int
+    rank*: int
+    firstPlaces*: int
+    survivalCount*: int
+
+  BattleResult* = object
+    bots*: seq[string]
+    rounds*: seq[RoundResult]
+    results*: seq[BotResult]
+    winners*: seq[string]  # bots with rank == 1
+
+proc parseServerOutput*(stdout: string): BattleResult =
+  for line in stdout.splitLines():
+    let s = line.strip()
+    if s.len == 0 or s[0] != '{': continue
+    let node = parseJson(s)
+    case node["event"].getStr()
+    of "game_started":
+      result.bots = node["bots"].getElems().mapIt(it.getStr())
+    of "round_ended":
+      var rr = RoundResult(round: node["round"].getInt())
+      for r in node["results"].getElems():
+        rr.results.add BotRoundResult(
+          name:     r["name"].getStr(),
+          score:    r["score"].getInt(),
+          rank:     r["rank"].getInt(),
+          survived: r["survived"].getBool()
+        )
+      result.rounds.add rr
+    of "battle_ended":
+      for r in node["results"].getElems():
+        result.results.add BotResult(
+          name:          r["name"].getStr(),
+          totalScore:    r["totalScore"].getInt(),
+          rank:          r["rank"].getInt(),
+          firstPlaces:   r["firstPlaces"].getInt(),
+          survivalCount: r["survivalCount"].getInt()
+        )
+      result.winners = result.results.filterIt(it.rank == 1).mapIt(it.name)
+    else: discard
+
+when isMainModule:
+  const sample = """
+{"event":"game_started","bots":["Alpha","Beta"]}
+{"event":"round_ended","round":1,"results":[{"name":"Alpha","score":150,"rank":1,"survived":true},{"name":"Beta","score":80,"rank":2,"survived":false}]}
+{"event":"round_ended","round":2,"results":[{"name":"Beta","score":200,"rank":1,"survived":true},{"name":"Alpha","score":60,"rank":2,"survived":false}]}
+{"event":"battle_ended","results":[{"name":"Alpha","totalScore":500,"rank":1,"firstPlaces":3,"survivalCount":5},{"name":"Beta","totalScore":300,"rank":2,"firstPlaces":1,"survivalCount":2}]}
+
+not json, should be ignored
+"""
+  let br = parseServerOutput(sample)
+  assert br.bots == @["Alpha", "Beta"]
+  assert br.rounds.len == 2
+  assert br.rounds[0].round == 1
+  assert br.rounds[0].results[0].name == "Alpha"
+  assert br.rounds[0].results[0].score == 150
+  assert br.rounds[0].results[0].rank == 1
+  assert br.rounds[0].results[0].survived == true
+  assert br.rounds[1].results[0].name == "Beta"
+  assert br.rounds[1].results[1].survived == false
+  assert br.results.len == 2
+  assert br.results[0].name == "Alpha"
+  assert br.results[0].totalScore == 500
+  assert br.results[0].firstPlaces == 3
+  assert br.results[0].survivalCount == 5
+  assert br.winners == @["Alpha"]
+  echo "all assertions passed"