feat: inline review comments on specific lines

Findings that reference a file+line within the diff are now posted as
inline comments directly on that line, in addition to appearing in the
summary table. Findings outside the diff range stay in the body only.

Implementation:
- gitea/diff.go: ParseDiffNewLines extracts new-file line numbers from
  each hunk in the unified diff
- gitea/client.go: PostReview accepts optional []ReviewComment with
  path + new_position + body (omitempty when nil)
- cmd/review-bot/main.go: maps findings → inline comments when the line
  exists in the diff, passes them to PostReview

Tests:
- diff parser: multi-hunk, new files, empty diff, boundary lines
- PostReview: with comments, nil comments (omitted from payload)

cmd/review-bot/main.go

@@ -241,8 +241,24 @@ func main() {
 
 	sentinel := fmt.Sprintf("<!-- review-bot:%s -->", *reviewerName)
 
+	// Map findings to inline comments for lines present in the diff
+	diffRanges := gitea.ParseDiffNewLines(diff)
+	var inlineComments []gitea.ReviewComment
+	for _, f := range result.Findings {
+		if f.File != "" && f.Line > 0 && diffRanges.Contains(f.File, f.Line) {
+			inlineComments = append(inlineComments, gitea.ReviewComment{
+				Path:        f.File,
+				NewPosition: int64(f.Line),
+				Body:        fmt.Sprintf("**[%s]** %s", f.Severity, f.Finding),
+			})
+		}
+	}
+	if len(inlineComments) > 0 {
+		log.Printf("Attaching %d inline comments", len(inlineComments))
+	}
+
 	log.Printf("Posting review (event=%s)...", event)
-	posted, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, event, reviewBody)
+	posted, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, event, reviewBody, inlineComments)
 	if err != nil {
 		log.Fatalf("Failed to post review: %v", err)
 	}
@@ -272,7 +288,7 @@ func main() {
 				if err := giteaClient.DeleteReview(ctx, owner, repoName, prNumber, posted.ID); err != nil {
 					log.Printf("Warning: could not delete review for escalation: %v", err)
 				} else {
-					_, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, "REQUEST_CHANGES", reviewBody)
+					_, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, "REQUEST_CHANGES", reviewBody, inlineComments)
 					if err != nil {
 						log.Printf("Warning: could not re-post as REQUEST_CHANGES: %v", err)
 					} else {