trace: add execution route visibility + debug passthrough; phase2170 canaries; docs

- Add HAKO_TRACE_EXECUTION to trace executor route
  - Rust hv1_inline: stderr [trace] executor: hv1_inline (rust)
  - Hakovm dispatcher: stdout [trace] executor: hakovm (hako)
  - test_runner: trace lines for hv1_inline/core/hakovm routes
- Add HAKO_VERIFY_SHOW_LOGS and HAKO_DEBUG=1 (enables both)
  - verify_v1_inline_file() log passthrough with numeric rc extraction
  - test_runner exports via HAKO_DEBUG
- Canary expansion under phase2170 (state spec)
  - Array: push×5/10 → size, len/length alias, per‑recv/global, flow across blocks
  - Map: set dup-key non-increment, value_state get/has
  - run_all.sh: unify, remove SKIPs; all PASS
- Docs
  - ENV_VARS.md: add Debug/Tracing toggles and examples
  - PLAN.md/CURRENT_TASK.md: mark 21.7 green, add Quickstart lines

All changes gated by env vars; default behavior unchanged.

tools/hako_check/tests/HC014_missing_entrypoint_case2/expected.json

@@ -0,0 +1,4 @@
+{"diagnostics":[
+  {"file":"ng.hako","line":1,"rule":"HC014","message":"[HC014] missing entrypoint (Main.main or main)","quickFix":"","severity":"warning"}
+]}
+

tools/hako_check/tests/HC014_missing_entrypoint_case2/ng.hako

@@ -0,0 +1,8 @@
+// ng.hako — missing Main box entirely (edge case)
+
+static box Utility {
+  method ping() {
+    return 1
+  }
+}
+