refactor: Quick Win cleanup - 102 lines deleted, zero regressions

Completed three high-efficiency refactoring tasks:

## Task 1: Pattern1Context deletion (40 lines)
- Removed deprecated Pattern1Context struct from simple_while_minimal.rs
- Removed context parameter from lowering pipeline
- Simplified API surface (one less unused type)
- Files: simple_while_minimal.rs, pattern1_minimal.rs, loop_to_join.rs

## Task 2: #[allow(dead_code)] cleanup (62 lines)
- Deleted new_with_outputs() from inline_boundary.rs (truly dead, deprecated)
- Deleted extract_type_hint() from generic_type_resolver.rs (future placeholder)
- Removed 3 incorrect annotations (code IS actually used)
- Added clear comments for future-work items

## Task 3: Test organization (0 lines, +26 doc lines)
- Added 4-section navigation to loop_scope_shape/tests.rs
- Improved test discoverability (17 tests → organized by module)
- Low-risk organization improvement
- Easy path for future per-module test file splitting

## Summary
- Total deletion: 102 net lines
- Files modified: 9
- Build status: ✅ Clean (0 errors, 0 warnings)
- Test status: ✅ 21/21 PASS
- Regressions: 0

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/mir/builder/control_flow/joinir/patterns/pattern1_minimal.rs

@@ -35,15 +35,14 @@ impl MirBuilder {
     /// # Phase 188-Impl-2: Host Variable Integration
     ///
     /// Extracts the loop variable from the host function (e.g., `i` from `i < 3`)
-    /// and passes it to the Pattern 1 lowerer along with a ValueId allocator.
+    /// and creates a JoinInlineBoundary for mapping between host and JoinIR ValueIds.
     ///
     /// # Pipeline
     /// 1. Extract loop variable name from condition
     /// 2. Look up ValueId in host variable_map
-    /// 3. Create Pattern1Context with host variable + allocator
-    /// 4. Call simple_while_minimal::lower_simple_while_minimal() → JoinModule
-    /// 5. convert_join_module_to_mir_with_meta() → MirModule
-    /// 6. Merge MIR blocks into current_function
+    /// 3. Call simple_while_minimal::lower_simple_while_minimal() → JoinModule
+    /// 4. convert_join_module_to_mir_with_meta() → MirModule
+    /// 5. Merge MIR blocks into current_function
     pub(in crate::mir::builder) fn cf_loop_pattern1_minimal(
         &mut self,
         condition: &ASTNode,
@@ -51,9 +50,7 @@ impl MirBuilder {
         _func_name: &str,
         debug: bool,
     ) -> Result<Option<ValueId>, String> {
-        use crate::mir::join_ir::lowering::simple_while_minimal::{
-            lower_simple_while_minimal, Pattern1Context,
-        };
+        use crate::mir::join_ir::lowering::simple_while_minimal::lower_simple_while_minimal;
         use crate::mir::BasicBlockId;
         use std::collections::{BTreeMap, BTreeSet};
 
@@ -89,16 +86,8 @@ impl MirBuilder {
             variable_definitions: BTreeMap::new(),
         };
 
-        // Phase 188-Impl-2: Create Pattern1Context with host variable + allocator
-        // Clone value_gen to move into closure
-        let mut value_gen_clone = self.value_gen.clone();
-        let ctx = Pattern1Context {
-            loop_var: loop_var_id,
-            value_allocator: Box::new(move || value_gen_clone.next()),
-        };
-
-        // Call Pattern 1 lowerer with host context
-        let join_module = match lower_simple_while_minimal(scope, Some(ctx)) {
+        // Call Pattern 1 lowerer
+        let join_module = match lower_simple_while_minimal(scope) {
             Some(module) => module,
             None => {
                 // Phase 195: Use unified trace