docs: update GOER.md — Phase 4 pgstore complete

GOER.md

@@ -1,6 +1,12 @@
 # Status from Go agent (ref-webi-go)
 
-## Completed
+## Completed (Phase 4)
+
+- [x] pgstore: PostgreSQL storage (pgx v5, double-buffer, CopyFrom bulk insert)
+- [x] storage.Store interface: added ListPackages(ctx); both fsstore and pgstore implement
+- [x] webid + webicached: -pg=<dsn> flag to select pgstore over fsstore
+
+## Completed (earlier)
 
 - [x] Libc classification: Rust static musl → `none`, hard-musl packages keep `musl`
 - [x] Windows gnu→none: MinGW self-contained
@@ -8,19 +14,21 @@
 - [x] pg asset_filter: server-only assets (includes client)
 - [x] comparecache field-level diffs: os/arch/libc/ext/channel with equivalence matching
 - [x] Go dist: use API structured os/arch (illumos/solaris kept distinct)
-- [x] sass: bare arm → armv7 (Dart Sass convention, per releases.js)
-- [x] ffmpeg: Windows .gz → ext exe (gzipped bare executables, per releases.js)
-- [x] Go dist: keep bare arm as-is (matches production)
+- [x] sass: bare arm → armv7 in classifier (Dart Sass targets ARMv7)
+- [x] LegacyBackport: separate core classifier (canonical) from legacy cache translation
+  - Go dist: armv6 → arm (prod keeps raw API value)
+  - ffmpeg: Windows .gz → exe (prod releases.js override)
 
-## comparecache status: 3 remaining diffs (all understood)
+## comparecache status: 3 remaining diffs (all production bugs)
 
-| Package | Field | Count | Issue |
-|---------|-------|-------|-------|
-| iterm2 | channel | 11 | Old 3.0.x versions: prod=beta, Go=stable. Edge case in URL-path detection. |
-| postgres | ext | 2 | Legacy EDB: prod=tar, Go=tar.gz. normalize.js quirk. |
-| terraform | channel | 14 | Go correctly detects alpha, prod misses it. Production bug. |
+| Package | Field | Count | Go (correct) | Prod (wrong) | Why |
+|---------|-------|-------|-------------|-------------|-----|
+| iterm2 | channel | 11 | stable | beta | Raw cache says stable (URL path `/stable/`). Prod misclassifies. |
+| postgres | ext | 2 | .tar.gz | tar | normalize.js strips compression layer. File IS .tar.gz. |
+| terraform | channel | 14 | alpha | stable | Version contains `-alpha-`. Prod regex misses it. |
 
 All other packages (98/101) have zero field-level disagreements.
+Not backporting these — Go is correct, production has bugs.
 
 ## Question for Researcher