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/HC013_duplicate_method_edge/expected.json

@@ -0,0 +1,3 @@
+{"diagnostics":[
+  {"file":"ng.hako","line":1,"rule":"HC013","message":"[HC013] duplicate method definition: Calculator.add/2 at line 11","quickFix":"","severity":"warning"}
+]}

tools/hako_check/tests/HC013_duplicate_method_edge/ng.hako

@@ -0,0 +1,22 @@
+// ng.hako — duplicate method with comments/whitespace between
+
+static box Calculator {
+  method add(a, b) {
+    return a + b
+  }
+
+  // some comment lines
+  // to ensure line numbers advance
+
+  method add(a, b) {
+    return a - b
+  }
+}
+
+static box Main {
+  method main() {
+    Calculator.add(1,2)
+    return 0
+  }
+}
+