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>

cmd/glint/main.go

@@ -420,9 +420,7 @@ Examples:
 	case "github":
 		writeGitHub(os.Stdout, findings)
 	default: // "text"
-		for _, f := range findings {
+		writeTextFindings(os.Stdout, findings)
-			fmt.Println(f)
-		}
 	}
 
 	if len(findings) == 0 {

cmd/glint/output.go

@@ -0,0 +1,111 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"git.k3nny.fr/glint/internal/linter"
+)
+
+// ANSI escape sequences used for colorized output.
+const (
+	ansiReset  = "\033[0m"
+	ansiBold   = "\033[1m"
+	ansiDim    = "\033[2m"
+	ansiRed    = "\033[31m"
+	ansiOrange = "\033[33m" // rendered as orange/amber in most terminals
+)
+
+// colorEnabled reports whether ANSI color should be used when writing to w.
+// Colors are suppressed when NO_COLOR is set or when w is not a terminal.
+func colorEnabled(w io.Writer) bool {
+	if os.Getenv("NO_COLOR") != "" {
+		return false
+	}
+	f, ok := w.(*os.File)
+	if !ok {
+		return false
+	}
+	fi, err := f.Stat()
+	return err == nil && (fi.Mode()&os.ModeCharDevice) != 0
+}
+
+// writeTextFindings prints findings in a columnized format with optional
+// ANSI color. All findings are scanned first to compute column widths so
+// that each field aligns across all output lines.
+//
+// Output columns (space-separated, no borders):
+//
+//	location   RULE   severity   message
+func writeTextFindings(w io.Writer, findings []linter.Finding) {
+	if len(findings) == 0 {
+		return
+	}
+
+	color := colorEnabled(w)
+
+	// Pre-compute locations and maximum location width.
+	locs := make([]string, len(findings))
+	maxLoc := 0
+	for i, f := range findings {
+		locs[i] = findingLocation(f)
+		if len(locs[i]) > maxLoc {
+			maxLoc = len(locs[i])
+		}
+	}
+
+	// Rule IDs are always 5 chars (GL001–GL999).
+	const ruleWidth = 5
+	// Severity width: "warning" = 7 chars.
+	const sevWidth = 7
+
+	for i, f := range findings {
+		loc := locs[i]
+		rule := f.Rule
+		sev := strings.ToLower(string(f.Severity))
+
+		msg := f.Message
+		if f.Job != "" {
+			msg = fmt.Sprintf("job %q: %s", f.Job, msg)
+		}
+
+		if color {
+			var sevSeq string
+			if f.Severity == linter.Error {
+				sevSeq = ansiRed + ansiBold
+			} else {
+				sevSeq = ansiOrange + ansiBold
+			}
+			fmt.Fprintf(w, "%s%-*s%s  %s%-*s%s  %s%-*s%s  %s\n",
+				ansiDim, maxLoc, loc, ansiReset,
+				ansiBold, ruleWidth, rule, ansiReset,
+				sevSeq, sevWidth, sev, ansiReset,
+				msg,
+			)
+		} else {
+			fmt.Fprintf(w, "%-*s  %-*s  %-*s  %s\n",
+				maxLoc, loc,
+				ruleWidth, rule,
+				sevWidth, sev,
+				msg,
+			)
+		}
+	}
+}
+
+// findingLocation formats the file:line:col location string for a finding.
+func findingLocation(f linter.Finding) string {
+	if f.File == "" {
+		return ""
+	}
+	switch {
+	case f.Line > 0 && f.Column > 0:
+		return fmt.Sprintf("%s:%d:%d", f.File, f.Line, f.Column)
+	case f.Line > 0:
+		return fmt.Sprintf("%s:%d", f.File, f.Line)
+	default:
+		return f.File
+	}
+}

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),
 				})
 			}

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
 	}
 

internal/model/pipeline.go

@@ -45,9 +45,10 @@ type Workflow struct {
 }
 
 type Job struct {
-	Name string // set by parser, not from YAML
+	Name   string // set by parser, not from YAML
-	File string // source file; set by Parse / resolver
+	File   string // source file; set by Parse / resolver
-	Line int    // line of the job key in its source file; set by parser
+	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)