feat: add prediction and omit empty Buy/Sell

internal/config/config.go

@@ -76,9 +76,10 @@ type AdvisorConfig struct {
 }
 
 // ArchiveConfig controls saving a local copy of each run's fetched data and
-// 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).
+// analysis. Archiving is always on: besides being a debugging aid, the last
+// few runs' report.md files are read back on every run to let the prompt
+// dedup against that rolling history (see archive.LoadRecent,
+// analyze.BuildUserPrompt).
 type ArchiveConfig struct {
 	// Dir is the directory each run's files are written under, one
 	// timestamped subdirectory per run. Supports a leading "~". Defaults to