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/pipeline.go

@@ -45,9 +45,10 @@ type Workflow struct {
 }
 
 type Job struct {
-	Name string // set by parser, not from YAML
-	File string // source file; set by Parse / resolver
-	Line int    // line of the job key in its source file; set by parser
+	Name   string // set by parser, not from YAML
+	File   string // source file; set by Parse / resolver
+	Line   int    // line of the job key in its source file; set by parser
+	Column int    // column of the job key (1-indexed); set by parser
 	Stage        string   `yaml:"stage"`
 	Script       any `yaml:"script"`       // []string or string (block scalar)
 	Run          any `yaml:"run"`          // alternative to script (CI steps)