feat(phase285w): Phase 285W-Syntax-0.1 - Reject weak(...) syntax (Parser-level Fail-Fast)

- Parser guard: Reject weak(...) with LPAREN check in parse_unary()
  - Error: "Use 'weak expr', not 'weak(expr)'" (helpful message)
  - Location: src/parser/expressions.rs:248-256
- MIR builder guard: Defense-in-depth for any bypassed cases
  - Location: src/mir/builder/calls/build.rs:37-46
- Rejection test: apps/tests/phase285w_weak_call_rejected.hako
- Smoke test: phase285w_weak_call_rejected_vm.sh (PASS ✅)
- Documentation:
  - EBNF.md: Add ~ (BitNot) to unary operators
  - lifecycle.md: Document weak(expr) as invalid syntax
  - phase-285/README.md: Add Phase 285W-Syntax-0.1 entry

Test results: 5/6 phase285 tests PASS (1 unrelated failure)
SSOT: docs/reference/language/lifecycle.md

Closes: Phase 285W-Syntax-0.1

src/mir/builder/calls/build.rs

@@ -34,6 +34,17 @@ impl MirBuilder {
             );
         }
 
+        // 0. Phase 285W-Syntax-0.1: Reject weak(...) function call syntax
+        // SSOT: docs/reference/language/lifecycle.md - weak <expr> is the ONLY valid syntax
+        if name == "weak" {
+            eprintln!("[Phase285W-0.1] Rejecting weak(...) function call");
+            return Err(format!(
+                "Invalid syntax: weak(...). Use unary operator: weak <expr>\n\
+                 Help: Change 'weak(obj)' to 'weak obj' (unary operator, no parentheses)\n\
+                 SSOT: docs/reference/language/lifecycle.md"
+            ));
+        }
+
         // 1. TypeOp wiring: isType(value, "Type"), asType(value, "Type")
         if let Some(result) = self.try_build_typeop_function(&name, &args)? {
             return Ok(result);