refactor: split source files that exceeded the ~300-line ceiling

Mechanical moves only — operations, store, history_view, and settings_view
are now split along their existing seams so every file stays within the 250+20%
guideline. Document the new layout in ARCHITECTURE.md and close the ROADMAP item.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/storage/store_config.go

@@ -0,0 +1,72 @@
+package storage
+
+import (
+	"encoding/json"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gitea.mixdep.ru/mix/gosentry/src/domain"
+)
+
+func loadOrCreateConfig(paths Paths) (domain.Config, error) {
+	// Defaults favor a portable installation: settings and jobs begin next to the
+	// executable, while logs are grouped under a dedicated subdirectory.
+	config := domain.DefaultConfig()
+
+	if _, err := os.Stat(paths.ConfigPath); errors.Is(err, os.ErrNotExist) {
+		return config, writeJSON(paths.ConfigPath, config)
+	}
+
+	data, err := os.ReadFile(paths.ConfigPath)
+	if err != nil {
+		return domain.Config{}, err
+	}
+	// Clearing the default first keeps "the file sets jobs_file" distinguishable
+	// from "the file omits it", which the jobs_dir migration below depends on.
+	// The fallbacks restore a value in either case.
+	config.JobsFile = ""
+	if err := json.Unmarshal(data, &config); err != nil {
+		return domain.Config{}, err
+	}
+
+	// A config written before the setting named a file carries jobs_dir instead
+	// of jobs_file. Keep its meaning by appending the fixed name that version
+	// used, then drop the old key so the file is rewritten in the current shape.
+	if strings.TrimSpace(config.JobsFile) == "" && strings.TrimSpace(config.JobsDir) != "" {
+		config.JobsFile = filepath.Join(config.JobsDir, JobsFileName)
+	}
+	config.JobsDir = ""
+	if strings.TrimSpace(config.JobsFile) == "" {
+		// Empty paths are treated as missing values rather than intentional root
+		// directories. This avoids accidentally writing jobs to unexpected places.
+		config.JobsFile = JobsFileName
+	}
+	if strings.TrimSpace(config.LogsDir) == "" {
+		config.LogsDir = "logs"
+	}
+	// MaxLogFiles and MaxLogAgeDays are deliberately not normalized: 0 means
+	// "keep everything" (see runner.CleanupLogs), not a missing value, so
+	// backfilling it here would make that choice impossible to persist. A config
+	// written before either field existed already carries 0 from json.Unmarshal
+	// leaving the DefaultConfig() value in config untouched, so old files still
+	// pick up 100 / 30 without an explicit backfill.
+	if config.ExecutionMode == "" {
+		config.ExecutionMode = domain.ExecutionModeParallel
+	}
+	if config.OverlapPolicy == "" {
+		config.OverlapPolicy = domain.OverlapPolicySkip
+	}
+	// DefaultTimeoutSeconds is deliberately not normalized: 0 is a meaningful
+	// value ("no timeout"), not a missing one, so backfilling it here would make
+	// the setting impossible to persist. Negative values are rejected by
+	// app.validateConfig before they can be saved.
+	if config.Theme == "" {
+		config.Theme = domain.ThemeGoSentry
+	}
+	if config.Theme == "default" {
+		config.Theme = domain.ThemeSystem
+	}
+	return config, nil
+}