feat: added block replace syntax with block edits in hashline parser

- Added `replace block N:` syntax in grammar/parser/tokenizer/types, emitting `kind: "block"` edits with empty-body checks.
- Added block-resolution in hashline apply/recovery, wiring `BlockResolver` to resolve edits with throw/drop unresolved behavior.
- Added native `blockRangeAt` support and exported block range/options types through pi-ast, pi-natives, and JS bindings.
- Added coding-agent resolver wiring plus internal visibility/exports updates and new parser, patcher, and setup-wizard tests.

packages/coding-agent/src/edit/hashline/block-resolver.ts

@@ -0,0 +1,14 @@
+/**
+ * Tree-sitter-backed {@link BlockResolver} for the hashline `replace block N:`
+ * operator. Bridges the pure hashline seam to the native `blockRangeAt`
+ * primitive in `@oh-my-pi/pi-natives`, which infers the language from the file
+ * path and returns the 1-indexed line span of the syntactic block beginning on
+ * the requested line (or `null` when none can be resolved).
+ */
+import type { BlockResolver } from "@oh-my-pi/hashline";
+import { blockRangeAt } from "@oh-my-pi/pi-natives";
+
+export const nativeBlockResolver: BlockResolver = ({ path, text, line }) => {
+	const range = blockRangeAt({ code: text, path, line });
+	return range ? { start: range.startLine, end: range.endLine } : null;
+};

packages/coding-agent/src/edit/hashline/diff.ts

@@ -22,6 +22,7 @@ import {
 import { resolveToCwd } from "../../tools/path-utils";
 import { generateDiffString } from "../diff";
 import { readEditFileText } from "../read-file";
+import { nativeBlockResolver } from "./block-resolver";
 
 export interface HashlineDiffOptions {
 	/**
@@ -74,7 +75,9 @@ export async function computeHashlineSectionDiff(
 		const normalized = normalizeToLF(content);
 		const hashError = validateSectionHash(section, absolutePath, normalized, snapshots);
 		if (hashError) return { error: hashError };
-		const result = options.streaming ? section.applyPartialTo(normalized) : section.applyTo(normalized);
+		const result = options.streaming
+			? section.applyPartialTo(normalized, nativeBlockResolver)
+			: section.applyTo(normalized, nativeBlockResolver);
 		if (normalized === result.text) return { error: `No changes would be made to ${section.path}.` };
 		return generateDiffString(normalized, result.text);
 	} catch (err) {

packages/coding-agent/src/edit/hashline/execute.ts

@@ -25,6 +25,7 @@ import { outputMeta } from "../../tools/output-meta";
 import { generateDiffString } from "../diff";
 import { getFileSnapshotStore } from "../file-snapshot-store";
 import type { EditToolDetails, EditToolPerFileResult, LspBatchRequest } from "../renderer";
+import { nativeBlockResolver } from "./block-resolver";
 import { HashlineFilesystem } from "./filesystem";
 import { type HashlineParams, hashlineEditParamsSchema } from "./params";
 
@@ -133,7 +134,7 @@ export async function executeHashlineSingle(
 		batchRequest: options.batchRequest,
 	});
 	const snapshots = getFileSnapshotStore(options.session);
-	const patcher = new Patcher({ fs, snapshots });
+	const patcher = new Patcher({ fs, snapshots, blockResolver: nativeBlockResolver });
 
 	// Single-section fast path: prepare, commit, render.
 	if (patch.sections.length === 1) {

packages/coding-agent/src/edit/hashline/index.ts

@@ -1,3 +1,4 @@
+export * from "./block-resolver";
 export * from "./diff";
 export * from "./execute";
 export * from "./filesystem";