Align documentation with clean baseline

docs/spec/08-current-product-backlog.md

@@ -14,11 +14,11 @@ requirements and intended sequencing, not proof of implementation.
   component model in phased work packages.
 - [x] Phase A: central protection catalog, validation, defaults and pure grouped
   BMK rules.
-- [x] Phase B1: additive relational schema, group backfill, component/protection
-  tables and shared BMK uniqueness.
-- [x] Phase B2: snapshot/transfer schema upgrade and deterministic compatibility
-  mapping.
-- [x] Phase C1: versioned new-board command with three groups and fixed header
+- [x] Phase B1: relational group, component and protection tables with shared
+  BMK uniqueness.
+- [x] Phase B2: complete snapshot/transfer schema for the supported project
+  state.
+- [x] Phase C1: new-board command with three groups and fixed header
   components.
 - [x] Phase C2a1: persistent insert/delete commands for mutable group
   protection and auxiliary components.
@@ -52,22 +52,22 @@ requirements and intended sequencing, not proof of implementation.
 
 ## First Release Baseline
 
-Complete this immediately before the first supported release, once the schema
-and initial feature set are frozen:
+The pre-release cleanup established the following compatibility boundary:
 
-- Decide explicitly whether pre-release databases, portable JSON exports,
-  logical snapshots and persisted command histories remain supported.
-- Create one clean baseline migration that builds the complete release schema
-  on an empty database.
-- Replace the active development migration chain and Drizzle metadata only if
-  no released installation depends on it.
-- Remove upgrade-only database, snapshot and command compatibility code only
-  for formats that are explicitly declared unsupported.
-- Preserve the pre-release migration history in Git history or a release tag.
-- Verify installation, migrations, application startup and core workflows
-  against a completely empty database.
-- Mark the resulting compatibility boundary with the first release tag.
-- Treat every migration published after that release as immutable.
+- [x] Pre-release databases, portable JSON exports, logical snapshots and
+  persisted command histories are explicitly unsupported.
+- [x] Migration `0000` builds the complete supported schema on an empty
+  database.
+- [x] The development migration chain and Drizzle metadata were replaced
+  before any supported release depended on them.
+- [x] Upgrade-only database, snapshot and command compatibility paths were
+  removed.
+- [x] Pre-cleanup development history remains available through Git history.
+- [x] Clean installation, migration, startup and core workflows were verified
+  against an empty database.
+- [ ] Mark this compatibility boundary with the first supported release tag.
+- After that release, every published migration is immutable and later schema
+  changes must use new additive migrations.
 
 ## Project History
 
@@ -109,9 +109,9 @@ and initial feature set are frozen:
   device rows with a valid phase are three-phase.
 - [x] Changing project voltage settings updates all project devices and circuits
   atomically in the same persistent Undo/Redo step.
-- [x] Database migration `0019` and snapshot schema version `5` normalize older
-  stored values. Version-four and older imports remain supported and are
-  normalized while being upgraded.
+- [x] Baseline migration `0000` and project-state schema version `1` store only
+  the canonical derived values. Pre-release imports are intentionally
+  unsupported.
 
 ## Circuit List Power Summary