T3.5: Move display helpers to src/app/format.go

Extract pure display/formatting functions from the GUI:
- StatusText, EventText, DisplayFolder, DisplayArguments,
  DisplaySuccessExitCodes, DisplayRunMode, DisplayInvocation, DisplayIndex.

These have no Fyne dependencies and serve as a shared formatting layer for
the service to use (e.g. StatusText in the tests when mocking the GUI).
The GUI imports them as app.DisplayFolder(...) etc.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/app/format.go

@@ -0,0 +1,89 @@
+package app
+
+import (
+	"fmt"
+	"strings"
+
+	"gitea.mixdep.ru/mix/gosentry/src/domain"
+)
+
+// StatusText formats a job's current state for display: "Paused" if disabled,
+// else its runtime LastState (Ready, Running, Success, etc).
+func StatusText(j domain.Job, runtime *domain.JobRuntime) string {
+	if !j.Enabled {
+		return "Paused"
+	}
+	if runtime == nil {
+		return ""
+	}
+	return runtime.LastState
+}
+
+// EventText formats a run record for the History table, showing time, trigger,
+// job name, outcome state, detail, and log file (if any).
+func EventText(e domain.RunRecord) string {
+	trigger := e.Trigger
+	if trigger == "" {
+		trigger = "Unknown"
+	}
+	if e.LogFile != "" {
+		return fmt.Sprintf("%s  %s  %s  %s  %s  %s", e.Time, trigger, e.JobName, e.State, e.Detail, e.LogFile)
+	}
+	return fmt.Sprintf("%s  %s  %s  %s  %s", e.Time, trigger, e.JobName, e.State, e.Detail)
+}
+
+// DisplayFolder formats a job's folder for display: "(No folder)" if empty,
+// else the trimmed folder name.
+func DisplayFolder(folder string) string {
+	if strings.TrimSpace(folder) == "" {
+		return "(No folder)"
+	}
+	return strings.TrimSpace(folder)
+}
+
+// DisplayArguments formats a job's arguments for display: "(none)" if empty,
+// else the trimmed arguments.
+func DisplayArguments(arguments string) string {
+	if strings.TrimSpace(arguments) == "" {
+		return "(none)"
+	}
+	return strings.TrimSpace(arguments)
+}
+
+// DisplaySuccessExitCodes formats a job's success exit codes for display:
+// "0" (the default) if empty, else the trimmed codes.
+func DisplaySuccessExitCodes(codes string) string {
+	if strings.TrimSpace(codes) == "" {
+		return "0"
+	}
+	return strings.TrimSpace(codes)
+}
+
+// DisplayRunMode formats a job's execution mode: "Start only" or
+// "Wait for completion".
+func DisplayRunMode(job domain.Job) string {
+	if job.StartOnly {
+		return "Start only"
+	}
+	return "Wait for completion"
+}
+
+// DisplayInvocation formats a job's command and arguments for the jobs list,
+// joining them with spacing and collapsing newlines in arguments to spaces.
+func DisplayInvocation(job domain.Job) string {
+	if strings.TrimSpace(job.Arguments) == "" {
+		return job.Command
+	}
+	return job.Command + "    " + strings.ReplaceAll(strings.TrimSpace(job.Arguments), "\n", " ")
+}
+
+// DisplayIndex returns the position of jobIndex in the given slice of indexes,
+// or 0 if not found.
+func DisplayIndex(indexes []int, jobIndex int) int {
+	for display, index := range indexes {
+		if index == jobIndex {
+			return display
+		}
+	}
+	return 0
+}