microbatch cleanup pt.1 (#9328)

* microbatch cleanup pt.1: extract context builder, simplify is_incremental, consolidate materialization

- Extract `extend_microbatch_node_context` to decouple batch context setup from execution
- Extract `materialize_microbatch_model` into materialize.rs alongside other materialization fns
- Make `render_batch_sql` and `extend_microbatch_node_context` standalone (no TaskRunnerCtx dependency)
- Simplify `is_incremental`: early-return on full_refresh, drop RelationObject wrapper, drop redundant materialization check, remove unnecessary async
- Remove `BatchResult` struct and `execute_materialization_macro` duplication from microbatch.rs
- Cache materialization return value at call site (model.rs) like other materializations

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* fix clippy/fmt, remove unused get_original_file_contents_async, add changie

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* materialize.rs

* add res back

* cargo fmt / clippy

---------

Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>
GitOrigin-RevId: 0e00cce933f8e81a0e5d6f10f95af25270a8a730

Author: 2 people

crates/dbt-parser/src/utils.rs

@@ -22,7 +22,6 @@ use minijinja::machinery::{Span, WhitespaceConfig};
 use minijinja::syntax::SyntaxConfig;
 use serde::{Deserialize, Serialize};
 use std::collections::{BTreeMap, BTreeSet};
-use tokio::fs;
 
 use std::path::Path;
 use std::path::PathBuf;
@@ -125,15 +124,6 @@ pub fn get_original_file_contents(in_dir: &Path, original_file_path: &PathBuf) -
     stdfs::read_to_string(&absolute_path).ok()
 }
 
-/// Returns the contents of a file given an original_file_path and in_dir, async
-pub async fn get_original_file_contents_async(
-    in_dir: &Path,
-    original_file_path: &PathBuf,
-) -> Option<String> {
-    let absolute_path = in_dir.join(original_file_path);
-    fs::read_to_string(&absolute_path).await.ok()
-}
-
 /// Prepares package dependencies for resolution and sets thread local dependencies.
 ///
 /// This function: