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_parser/parser_core.hako

@@ -1,5 +1,4 @@
 // tools/hako_parser/parser_core.hako - HakoParserCoreBox (token-based MVP)
-using selfhost.shared.common.string_helpers as Str
 using tools.hako_parser.tokenizer as HakoTokenizerBox
 
 static box HakoParserCoreBox {
@@ -47,8 +46,13 @@ static box HakoParserCoreBox {
         continue
       }
       if me._eq(t, "INCLUDE") == 1 {
-        // include "path"
-        p = me._advance(p, N); local s=me._peek(toks, p, N); if me._eq(s, "STRING") == 1 { ast.get("includes").push(Str.int_to_str(s.get("line"))); p = me._advance(p, N) }
+        // include "path" (record line for diagnostics as string to keep emitter simple)
+        p = me._advance(p, N)
+        local s = me._peek(toks, p, N)
+        if me._eq(s, "STRING") == 1 {
+          local ln = s.get("line"); if ln == null { ln = 0 }
+          ast.get("includes").push(me._itoa(ln)); p = me._advance(p, N)
+        }
         continue
       }
       if me._eq(t, "STATIC") == 1 {
@@ -115,6 +119,12 @@ static box HakoParserCoreBox {
   _peek(toks, idx, N) { if idx >= N { return null } return toks.get(idx) }
   _eq(t, kind) { if t == null { return 0 } if t.get("type") == kind { return 1 } return 0 }
   _advance(p, N) { if p < N { return p + 1 } return p }
+  _itoa(n) {
+    local v = 0 + n; if v == 0 { return "0" }
+    local digits = "0123456789"; local out = ""; local tmp = ""
+    while v > 0 { local d = v % 10; tmp = digits.substring(d,d+1) + tmp; v = v / 10 }
+    out = tmp; return out
+  }
 }
 
 static box HakoParserCoreMain { method main(args) { return 0 } }