fix: use paragraph breaks between hover detail lines (#528)

## Summary
- Fix hover markdown rendering where detail lines (Dependencies, Group,
Inputs, Outputs) appeared inline instead of on separate lines
- Changed detail join separator from single `\n` (spread into lines
array) to `\n\n` (paragraph breaks) so markdown renderers display each
detail on its own line

Closes #514

## Test plan
- [x] Added test verifying `**Dependencies**: build\n\n**Group**:
publish` paragraph break formatting
- [x] All 52 language-server tests pass

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

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: nam-hle

packages/language-server/src/hover.ts

@@ -35,7 +35,7 @@ function formatHoverContent(reg: TaskRegistration): string {
 		}
 
 		if (details.length > 0) {
-			lines.push("", "---", ...details);
+			lines.push("", "---", details.join("\n\n"));
 		}
 	}
 

packages/language-server/test/hover.test.ts

@@ -76,6 +76,18 @@ describe("getHover", () => {
 		expect(value).toContain("**compile**");
 	});
 
+	it("separates detail lines with paragraph breaks", async () => {
+		const { doc, analysis } = await setupFixture("valid.ts");
+		const content = doc.getText();
+		const offset = findStringOffset(content, "release");
+		const position = doc.positionAt(offset);
+		const hover = getHover(analysis, position, doc);
+
+		expect(hover).not.toBeNull();
+		const value = (hover!.contents as { value: string }).value;
+		expect(value).toContain("**Dependencies**: build\n\n**Group**: publish");
+	});
+
 	it("returns null for non-task strings", async () => {
 		const { doc, analysis } = await setupFixture("valid.ts");
 		const position = doc.positionAt(0);