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/linter/dependencies.go

@@ -30,6 +30,7 @@ func checkDependencies(p *model.Pipeline, skipped map[string]bool) []Finding {
 					Job:      name,
 					File:     job.File,
 					Line:     job.Line,
+					Column:   job.Column,
 					Message:  fmt.Sprintf("'dependencies' references unknown job %q", dep),
 				})
 				continue
@@ -43,6 +44,7 @@ func checkDependencies(p *model.Pipeline, skipped map[string]bool) []Finding {
 						Job:      name,
 						File:     job.File,
 						Line:     job.Line,
+						Column:   job.Column,
 						Message:  fmt.Sprintf("'dependencies' job %q must be in an earlier stage (in %q, current job is in %q)", dep, depJob.Stage, job.Stage),
 					})
 				}

internal/linter/if_reachability.go

@@ -99,6 +99,7 @@ func evalRulesReachability(name string, job model.Job, jobVars map[string]string
 		Job:      name,
 		File:     job.File,
 		Line:     job.Line,
+		Column:   job.Column,
 		Message:  "rules: block can never activate: all if: conditions evaluate to false given the declared pipeline variables",
 	}
 }

internal/linter/inherit_completeness.go

@@ -40,6 +40,7 @@ func checkJobInheritCompleteness(p *model.Pipeline, name string, job model.Job)
 			Job:      name,
 			File:     job.File,
 			Line:     job.Line,
+			Column:   job.Column,
 			Message:  "'inherit: default:' is declared but the pipeline has no 'default:' block — declaration has no effect",
 		}}
 	}
@@ -70,6 +71,7 @@ func checkJobInheritCompleteness(p *model.Pipeline, name string, job model.Job)
 		Job:      name,
 		File:     job.File,
 		Line:     job.Line,
+		Column:   job.Column,
 		Message: fmt.Sprintf(
 			"'inherit: default: [%s]': %s not defined in the 'default:' block — %s",
 			strings.Join(dead, ", "),

internal/linter/linter.go

@@ -22,15 +22,19 @@ type Finding struct {
 	Job      string // empty for pipeline-level findings
 	File     string // source file where the finding originates
 	Line     int    // line number in File (0 = unknown)
+	Column   int    // column number in File (0 = unknown; 1-indexed)
 	Message  string
 }
 
 func (f Finding) String() string {
 	var loc string
 	if f.File != "" {
-		if f.Line > 0 {
+		switch {
+		case f.Line > 0 && f.Column > 0:
+			loc = fmt.Sprintf("%s:%d:%d: ", f.File, f.Line, f.Column)
+		case f.Line > 0:
 			loc = fmt.Sprintf("%s:%d: ", f.File, f.Line)
-		} else {
+		default:
 			loc = fmt.Sprintf("%s: ", f.File)
 		}
 	}
@@ -225,6 +229,7 @@ func checkJob(name string, job model.Job, stageSet map[string]bool) []Finding {
 		if findings[i].Job != "" && findings[i].File == "" {
 			findings[i].File = job.File
 			findings[i].Line = job.Line
+			findings[i].Column = job.Column
 		}
 	}
 	return findings

internal/linter/needs.go

@@ -53,6 +53,7 @@ func checkNeeds(p *model.Pipeline, skipped map[string]bool) []Finding {
 					Job:      name,
 					File:     job.File,
 					Line:     job.Line,
+					Column:   job.Column,
 					Message:  fmt.Sprintf("needs unknown job %q", entry.job),
 				})
 				continue
@@ -71,6 +72,7 @@ func checkNeeds(p *model.Pipeline, skipped map[string]bool) []Finding {
 						Job:      name,
 						File:     job.File,
 						Line:     job.Line,
+						Column:   job.Column,
 						Message: fmt.Sprintf(
 							"needs %q which is in a later stage (%q after %q)",
 							entry.job, neededJob.Stage, job.Stage,
@@ -111,6 +113,7 @@ func checkRulesNeeds(p *model.Pipeline, skipped map[string]bool) []Finding {
 						Job:      name,
 						File:     job.File,
 						Line:     job.Line,
+						Column:   job.Column,
 						Message: fmt.Sprintf(
 							"rules[%d].needs: references unknown job %q",
 							i, entry.job,
@@ -171,6 +174,7 @@ func detectNeedsCycles(graph map[string][]string, jobs map[string]model.Job) []F
 					Job:      name,
 					File:     j.File,
 					Line:     j.Line,
+					Column:   j.Column,
 					Message:  fmt.Sprintf("circular dependency in needs: %v → %s", path, name),
 				})
 			}

internal/linter/variables.go

@@ -148,6 +148,7 @@ func checkVariableRefs(p *model.Pipeline) []Finding {
 					Job:      name,
 					File:     job.File,
 					Line:     job.Line,
+					Column:   job.Column,
 					Message:  fmt.Sprintf("rules[%d].if: $%s is not declared in pipeline or job variables:", i, varName),
 				})
 			}