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.

nyash.toml

@@ -182,6 +182,7 @@ path = "lang/src/shared/common/string_helpers.hako"
 
 # Phase 20.34 — Box‑First selfhost build line (aliases for Hako boxes)
 "hako.mir.builder" = "lang/src/mir/builder/MirBuilderBox.hako"
+"hako.mir.builder.pattern_registry" = "lang/src/mir/builder/pattern_registry.hako"
 "hako.llvm.emit" = "lang/src/llvm_ir/emit/LLVMEmitBox.hako"
 "hako.mir.builder.internal.prog_scan" = "lang/src/mir/builder/internal/prog_scan_box.hako"
 "hako.mir.builder.internal.pattern_util" = "lang/src/mir/builder/internal/pattern_util_box.hako"