chore: land the remaining low-severity items from the whole-project review

Phase 11 of PROJECT_REVIEW_PLAN.md: the themed cleanup pass over every
low-severity finding still open (2.2-2.3, 3.4-3.6, 4.3-4.7, 6.4-6.7,
7.1-7.3, 8.2-8.3, 9.1-9.4, and the under-documented decisions in §10/§11).

Behavioral fixes:
- Reassign duplicate job IDs in a hand-edited jobs.json instead of letting
  two jobs share one runtime, schedule entry, and SeedStats bucket.
- Disambiguate run-log file names that collide within the same second.
- Compute AvgDurationMS as DurationSumMS/TimedRunCount instead of an
  incremental integer mean, so it always matches the seeded-from-logs
  average instead of drifting from truncation error.
- Clean absolute paths in ResolveConfiguredPath so two spellings of the
  same jobs file do not trigger a spurious adoption.
- Report InstallDesktopIcon failures through ErrorOccurred instead of
  discarding them silently.
- Move settingsView's blocking AutostartStatus (PowerShell on Windows) off
  the UI thread.
- Give notify-timing.tsv its own extension so CleanupLogs no longer
  manages it as a run log.
- Replace the settingsView Save handler's second copy of validateConfig's
  rules with a bare parse, letting the Service's own error surface.

Cleanups:
- Delete collectActivity, the dead yaml tags on RunRecord, and the
  logArguments/LogArguments alias.
- Fold the two systemTrayRegistered/mainWindowHidden globals into one
  trayState instance Run owns and threads through Settings and the
  single-instance reveal path.
- Fix stale comments/docs: the frozen window-size restore claim, a
  reference to a renamed recordRun, README's "Pause all" and notification
  wording, the PowerShell quoting note for TESTS.md's coverage command,
  and scripts/test.bat's UTF-8 checkmarks under a non-UTF-8 code page.
- Document the single-instance fallback's consequence and the
  unauthenticated instance-channel port in STANDARDS.md; record the
  config-shim retirement plan in ROADMAP.md.

3.5, 7.3, and 9.4 turned out to already be fixed by earlier phases; no
change needed for those three.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/ui/history_view_test.go

@@ -6,8 +6,6 @@ import (
 	"testing"
 	"time"
 
-	"gitea.mixdep.ru/mix/gosentry/src/domain"
-
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/test"
 	"fyne.io/fyne/v2/widget"
@@ -57,31 +55,6 @@ func TestIndexOfID(t *testing.T) {
 	}
 }
 
-func TestCollectActivityMergesAndSorts(t *testing.T) {
-	jobs := []job{
-		{ID: 1, Name: "A"},
-		{ID: 2, Name: "B"},
-	}
-	runtimes := map[int]*domain.JobRuntime{
-		1: {Logs: []domain.RunRecord{{Time: "2026-01-02 10:00:00", JobID: 1}}},
-		2: {Logs: []domain.RunRecord{{Time: "2026-01-01 09:00:00", JobID: 2}}},
-	}
-	got := collectActivity(jobs, runtimes)
-	if len(got) != 2 {
-		t.Fatalf("len = %d, want 2", len(got))
-	}
-	if got[0].Time != "2026-01-01 09:00:00" || got[1].Time != "2026-01-02 10:00:00" {
-		t.Errorf("sort order = %v, want ascending by Time", got)
-	}
-}
-
-func TestCollectActivitySkipsMissingRuntimes(t *testing.T) {
-	jobs := []job{{ID: 1, Name: "A"}}
-	if got := collectActivity(jobs, nil); len(got) != 0 {
-		t.Errorf("nil runtimes: got %v, want empty", got)
-	}
-}
-
 func TestHistoryCellText(t *testing.T) {
 	events := []event{{
 		Time:    "2026-06-01 12:00:00",