Rename module to activeblue_familylaw_v2 (coexist with legacy prod module)

Production already has a DIFFERENT, earlier module installed as `activeblue_familylaw`
(models fl.*, real data). Renamed this build's technical name to
`activeblue_familylaw_v2` so it installs ALONGSIDE the legacy app instead of replacing
it. Models (familylaw.*) and test tags (familylaw_step<N>) are unchanged — only the
module name and its group XML IDs change.

Changes:
- Folder activeblue_familylaw -> activeblue_familylaw_v2 (git mv)
- All 44 dotted refs activeblue_familylaw. -> activeblue_familylaw_v2.
  (security group XML IDs in views/python; test patch targets odoo.addons.*)
- Manifest display name -> "Active Blue Family Law v2"; root menu -> "Family Law (v2)"
- scripts/validate_module.py ROOT path; BUILD_STATUS.md run commands + coexistence
  note; START_HERE.md pointer

Verified in live Odoo 18:
- Fresh install + full suite: 200 tests, 0 failed, 0 errors.
- COEXISTENCE on a clone of prod db1: installing _v2 alongside the installed legacy
  activeblue_familylaw left the legacy untouched (still installed 18.0.1.0.0, fl.*
  models registered, fl_caselaw 25 rows intact) while adding the 30 familylaw.* models.
  Exit 0, no errors. Clone dropped; prod DBs untouched.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

START_HERE.md

@@ -1,5 +1,11 @@
 # START HERE — Claude Code kickoff
 
+> **Note (current state):** the module is fully built (Steps 1–14) and its technical
+> name is now **`activeblue_familylaw_v2`** (renamed from `activeblue_familylaw` to
+> coexist with a different legacy module of that name already in production). The
+> design docs below still say `activeblue_familylaw` — that's the historical narrative;
+> the live module folder/name is `activeblue_familylaw_v2`. See `BUILD_STATUS.md`.
+
 You are picking up an in-progress build. Read in this order, then start the task at
 the bottom. Do **not** re-derive the design — it exists; follow it.