refactor(p2-65): 🏗️ Phase 5 C3 — drop dead mc-turn deps from read-only consumers (bullet 5)

After C2 retargeted all state-shape reads onto mc-state, three crates carry
no remaining `mc_turn::` usage of any kind:
- mc-save: 0 mc_turn refs → drop `mc-turn` dep (keeps mc-state).
- mc-vision: 0 mc_turn refs → drop `mc-turn` dep (keeps mc-state).
- mc-mcts-service: only a doc-comment referenced mc_turn; code uses mc-ai
  alone → drop the dead `mc-turn` dep (verified `cargo build -p
  mc-mcts-service` green without it).

api-gdext / mc-player-api / mc-sim KEEP mc-turn — they genuinely invoke
turn-step logic (TurnProcessor, action_handlers, courier_resolver, chronicle,
VictoryConfig, combat_balance loader). mc-turn KEEPS its mc-ai dep — it calls
mc_ai ransom-decision / abstract-projection / ScoringWeights helpers during
turn resolution (8 sites); that is logic dispatch, not a state-data cycle.

Gates (apricot): cargo test --workspace --no-run exit 0; serde_roundtrip 6/6;
full_turn_golden 3/3; mc-save 5+5+1; mc-vision 29/29 (1 ignored).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/simulator/Cargo.lock

@@ -1854,7 +1854,6 @@ version = "0.1.0"
 dependencies = [
  "bincode",
  "mc-ai",
- "mc-turn",
  "serde",
  "serde_json",
  "thiserror 1.0.69",
@@ -1941,7 +1940,6 @@ version = "0.1.0"
 dependencies = [
  "mc-core",
  "mc-state",
- "mc-turn",
  "mc-vision",
  "serde",
  "serde_json",
@@ -2068,7 +2066,6 @@ dependencies = [
  "mc-core",
  "mc-replay",
  "mc-state",
- "mc-turn",
  "serde",
  "serde_json",
 ]

src/simulator/crates/mc-mcts-service/Cargo.toml

@@ -9,7 +9,6 @@ path = "src/bin/mcts-server.rs"
 
 [dependencies]
 mc-ai       = { path = "../mc-ai" }
-mc-turn     = { path = "../mc-turn" }
 serde       = { workspace = true }
 serde_json  = { workspace = true }
 bincode     = { version = "2", features = ["serde"] }

src/simulator/crates/mc-save/Cargo.toml

@@ -15,7 +15,6 @@ thiserror    = "1"
 [dev-dependencies]
 mc-vision    = { path = "../mc-vision" }
 mc-state     = { path = "../mc-state" }
-mc-turn      = { path = "../mc-turn" }
 
 [lints]
 workspace = true

src/simulator/crates/mc-vision/Cargo.toml

@@ -6,7 +6,6 @@ edition = "2021"
 [dependencies]
 mc-core = { path = "../mc-core" }
 mc-state = { path = "../mc-state" }
-mc-turn = { path = "../mc-turn" }
 mc-replay = { path = "../mc-replay" }
 serde.workspace      = true
 serde_json.workspace = true