feat: dedup and format the output

internal/config/config.go

@@ -76,13 +76,13 @@ type AdvisorConfig struct {
 }
 
 // ArchiveConfig controls saving a local copy of each run's fetched data and
-// analysis — useful for debugging prompt/parsing issues without needing to
-// reproduce a live run.
+// analysis. Archiving is always on: besides being a debugging aid, the
+// previous run's report.md is read back on every run to let the prompt
+// dedup against it (see analyze.BuildUserPrompt).
 type ArchiveConfig struct {
-	Enabled bool `yaml:"enabled"`
 	// Dir is the directory each run's files are written under, one
 	// timestamped subdirectory per run. Supports a leading "~". Defaults to
-	// "~/.local/state/stonks/runs" if enabled with Dir left empty.
+	// "~/.local/state/stonks/runs" if left empty.
 	Dir string `yaml:"dir"`
 }