Selfhost: EXE path switched to Program(JSON v0) → MIR(JSON) → ny-llvmc; BuildBox opts (structured via env/array) and Bridge v1 positive canary

- selfhost_build.sh: EXE now converts Stage‑B Program(JSON v0) to MIR(JSON) via --json-file + --program-json-to-mir, then feeds ny-llvmc
- BuildBox: accept minimal opts via env or simple array parsing (alias_table, require_mods)
- Add positive v1 bridge canary: canonicalize_method_size_on_array_vm.sh (quick)

src/cli/mod.rs

@@ -59,6 +59,7 @@ pub struct CliConfig {
     pub build_target: Option<String>,
     pub cli_usings: Vec<String>,
     pub emit_mir_json: Option<String>,
+    pub program_json_to_mir: Option<String>,
     pub emit_exe: Option<String>,
     pub emit_exe_nyrt: Option<String>,
     pub emit_exe_libs: Option<String>,
@@ -118,6 +119,7 @@ impl CliConfig {
             emit: EmitConfig {
                 emit_cfg: self.emit_cfg.clone(),
                 emit_mir_json: self.emit_mir_json.clone(),
+                program_json_to_mir: self.program_json_to_mir.clone(),
                 emit_exe: self.emit_exe.clone(),
                 emit_exe_nyrt: self.emit_exe_nyrt.clone(),
                 emit_exe_libs: self.emit_exe_libs.clone(),
@@ -190,6 +192,7 @@ impl Default for CliConfig {
             build_target: None,
             cli_usings: Vec::new(),
             emit_mir_json: None,
+            program_json_to_mir: None,
             emit_exe: None,
             emit_exe_nyrt: None,
             emit_exe_libs: None,