docs: add Phase 130 plan and set Now to Phase 130

docs/development/current/main/phases/phase-130/README.md

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+# Phase 130: if-only Normalized “Small Expr/Assign” Expansion (dev-only)
+
+Status: PLAN (P0–P3)
+Scope: if-only Normalized（StepTree → Normalized shadow pipeline）
+Related:
+- Entry: `docs/development/current/main/10-Now.md`
+- Phase 129 (join_k/post_k): `docs/development/current/main/phases/phase-129/README.md`
+- ControlTree SSOT: `docs/development/current/main/design/control-tree.md`
+
+## Goal
+
+Increase usefulness of the if-only Normalized path without touching loop lowering yet:
+
+- Enable minimal post-if computation (`x = x + 3`) and returns via env.
+- Keep **PHI禁止**: merge via env + continuations only.
+- Keep **dev-only** and **既定挙動不変**: unmatched shapes fall back (strict can Fail-Fast for fixtures).
+
+## Non-Goals
+
+- No loops (Loop/Break/Continue still rejected by capability guard).
+- No general expression lowering (start with one narrow shape only).
+- No new env vars (use existing `joinir_dev_enabled()` / `joinir_strict_enabled()`).
+
+## Work Items (P0–P3)
+
+### P0: Fixtures + Smokes (VM + LLVM EXE)
+
+Add a “post-if update then return” fixture that forces post_k to execute and tests env updates:
+
+- New fixture: `apps/tests/phase130_if_only_post_if_add_min.hako`
+  - Case A: `flag=1` → expected `5`
+  - Case B: `flag=0` → expected `4`
+  - Output: `5\n4`
+- Smokes (integration):
+  - `tools/smokes/v2/profiles/integration/apps/phase130_if_only_post_if_add_vm.sh`
+  - `tools/smokes/v2/profiles/integration/apps/phase130_if_only_post_if_add_llvm_exe.sh`
+  - Use `output_validator.sh` numeric-line assertion.
+  - LLVM EXE smoke uses `llvm_exe_runner.sh` + plugin gating.
+
+Acceptance:
+- `phase130_*_vm.sh` PASS
+- `phase130_*_llvm_exe.sh` PASS (SKIP allowed only if LLVM prerequisites missing; plugin prerequisites should be satisfied via existing runner)
+
+### P1: Assign(Variable) minimal
+
+Support `x = y` inside post_k (and/or inside branches) for if-only:
+
+- Only local variables (no field/property assign).
+- RHS must resolve from env (`writes` or `inputs`).
+- strict: unsupported shapes → `freeze_with_hint("phase130/assign/var/unsupported", ...)`.
+
+### P2: Assign(Add) minimal for integers
+
+Support `x = x + <int literal>` (exact shape) in post_k:
+
+- Strictly `Var + IntLiteral` with `lhs_var == dst_var` (no commutation, no general binop).
+- Type: integer only (string concat stays out-of-scope; Fail-Fast under strict).
+
+### P3: Verifier tightening (env writes-only discipline)
+
+Add a structural check to ensure env updates only target `writes` fields:
+
+- In Normalized emission, any “env update” must update a field that exists in `EnvLayout.writes`.
+- Writing to an `inputs` field is prohibited (strict Fail-Fast).
+
+## Verification
+
+Commands:
+
+```bash
+cargo test --lib
+
+# New Phase 130 smokes
+bash tools/smokes/v2/profiles/integration/apps/phase130_if_only_post_if_add_vm.sh
+bash tools/smokes/v2/profiles/integration/apps/phase130_if_only_post_if_add_llvm_exe.sh
+
+# Regressions (minimum)
+bash tools/smokes/v2/profiles/integration/apps/phase129_if_only_post_if_return_var_vm.sh
+bash tools/smokes/v2/profiles/integration/apps/phase129_join_k_as_last_vm.sh
+bash tools/smokes/v2/profiles/integration/apps/phase128_if_only_partial_assign_normalized_vm.sh
+```
+
+## Notes
+
+- Phase 130 intentionally stays “if-only” to keep the change-set small and correctness-focused.
+- Loop lowering in Normalized is a separate phase; do not mix scopes.
+