feat(cli): colorized, columnized text output with line:col locations

Replace the per-line fmt.Println loop with writeTextFindings() in
cmd/glint/output.go. The new renderer:

- Aligns all findings into four space-separated columns: location,
  rule ID, severity, message — widths computed from the full finding
  set so all lines are flush
- Colors severity words when stdout is a TTY and NO_COLOR is not set:
  red+bold for "error", orange+bold for "warning"; location dimmed;
  rule ID bold
- Formats location as file:line:col when column is known, file:line
  otherwise, falling back to just file

To populate column numbers, add Column int to model.Job (set from
keyNode.Column in the YAML parser) and Finding.Column (set during
the checkJob source-location attachment pass and in the ten cross-job
check sites that explicitly set Line: job.Line).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/model/parser.go

@@ -83,7 +83,8 @@ func ParseBytes(data []byte) (*Pipeline, error) {
 			return nil, fmt.Errorf("parsing job %q: %w", key, err)
 		}
 		j.Name = key
-		j.Line = keyNode.Line // exact line of the job name key
+		j.Line = keyNode.Line     // exact line of the job name key
+		j.Column = keyNode.Column // exact column of the job name key
 		p.Jobs[key] = j
 	}