Phase 21.6 solidification: chain green (return/binop/loop/call); add Phase 21.7 normalization plan (methodize static boxes). Update CURRENT_TASK.md and docs.

docs/development/roadmap/phases/phase-21.6-solidification/CHECKLIST.md

@@ -6,16 +6,48 @@ Acceptance (all must be green on this host)
 - VM: MIR(JSON) for minimal loop returns 10
 - ny‑llvmc(crate) EXE: returns 10
 
+Canaries to run
+- bash tools/dev/stageb_loop_json_canary.sh
+- bash tools/dev/phase216_chain_canary.sh
+- bash tools/dev/phase216_chain_canary_return.sh
+- bash tools/dev/phase216_chain_canary_binop.sh
+- bash tools/dev/phase216_chain_canary_loop.sh
+- bash tools/dev/phase216_chain_canary_call.sh (Phase 21.6 extension)
+
 Guardrails
 - No default behavior changes; all aids behind env toggles.
 - Logs quiet; tags/dev traces are opt‑in.
 - No llvmlite in default chain; crate backend is main line.
 
-Canaries to run
-- bash tools/dev/stageb_loop_json_canary.sh
-- bash tools/dev/phase216_chain_canary.sh
-
 Rollback
 - Parser fallback in parse_loop is conservative; remove after VM/gpos fix lands.
 - Keep canaries; they protect against regressions.
 
+## Phase 21.6 Call Support Extension
+
+**Toggles**:
+- `HAKO_STAGEB_FUNC_SCAN=1`: Enable function definition scanning in Stage-B
+- `HAKO_MIR_BUILDER_FUNCS=1`: Enable function definition lowering in MirBuilder (unused - Rust delegate used)
+
+**Implementation**:
+1. Stage-B function scanner extracts `method <name>(params){ body }` definitions
+2. Stage-B injects `defs` array into Program(JSON v0)
+3. Rust delegate (src/runner/json_v0_bridge/) processes `defs` and generates MIR functions
+4. Function names are qualified as `Box.method` (e.g., `Main.add`)
+
+**Current Status**:
+- ✅ Stage-B scanning implemented (compiler_stageb.hako)
+- ✅ Rust delegate defs processing implemented (ast.rs, lowering.rs)
+- ✅ MIR functions generated with correct signatures and bodies
+- ⚠️  Call resolution incomplete: calls still use dynamic string lookup ("add") instead of static Main.add reference
+
+**Next Steps for Call Completion**:
+- Need to resolve Call("add") → Call(Main.add) at lowering time
+- Implement call target resolution in json_v0_bridge/lowering.rs
+- Update Call instruction to use function reference instead of string
+- Alternative: use MirCall with Callee::Function for local calls
+
+**撤去条件 (Removal Criteria)**:
+- After Phase 22 introduces proper local function scoping with Callee typed calls
+- Or when unified with broader namespace/using system Phase 15.5+
+