feat(ci): tracing JSON format in CI, tick duration logging, schedule dump (#344, #346)

Tracing (#344):
- Add 'json' feature to tracing-subscriber dependency
- Emit JSON log format when CI=true or RUST_LOG_FORMAT=json is set
  (structured log ingestion in CI pipelines)
- Add tracing::debug! with tick_ms/budget_ms/over_budget fields on each
  tick for performance profiling and tier system debugging prerequisite

Schedule dump (#346):
- Add --dump-schedule CLI flag that prints bevy_ecs schedule graph and exits
  without requiring TCP bridge or world setup
- Add make debug-schedule target for CI artifact generation and diff-based
  regression detection of unintended system reordering

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

server/Cargo.lock

@@ -978,7 +978,7 @@ dependencies = [
 
 [[package]]
 name = "settled-reach-server"
-version = "0.1.10"
+version = "0.1.11"
 dependencies = [
  "bevy_app",
  "bevy_ecs",
@@ -1162,6 +1162,16 @@ dependencies = [
  "tracing-core",
 ]
 
+[[package]]
+name = "tracing-serde"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "704b1aeb7be0d0a84fc9828cae51dab5970fee5088f83d1dd7ee6f6246fc6ff1"
+dependencies = [
+ "serde",
+ "tracing-core",
+]
+
 [[package]]
 name = "tracing-subscriber"
 version = "0.3.22"
@@ -1172,12 +1182,15 @@ dependencies = [
  "nu-ansi-term",
  "once_cell",
  "regex-automata",
+ "serde",
+ "serde_json",
  "sharded-slab",
  "smallvec",
  "thread_local",
  "tracing",
  "tracing-core",
  "tracing-log",
+ "tracing-serde",
 ]
 
 [[package]]