docs(naming): adopt OS / Enhanced product-line framing + align with existing repos

Two product lines, named to make scope obvious to buyers:
- 🔒 SilverMetal OS — we ship the operating system or ROM
  (Linux, Pixel, Samsung-unlocked, Motorola-unlocked)
- 🛡️ SilverMetal Enhanced — we harden the OS the device already runs
  (Windows, macOS, iOS, generic Android)

Repo alignment:
- SilverVPN already exists as a SilverLABS product (server + MAUI client +
  Linux client + tunnel service). stack/vpn/ is now an integration pointer
  rather than a re-scaffold; per-platform READMEs reference it.
- SilverApple is deprecated; SilverMetal Enhanced — iOS supersedes it.
  Migration step added as roadmap milestone 3I.1.
- SilverDROID name clash explicitly noted as unrelated (it's the SilverSHELL
  AppStore Android client, not an Android ROM).
- SilverChat may overlap with SilverVPN.Client.Chat; alignment decision
  added as roadmap milestone 1.1.1.

Roadmap restructured: phases now track the OS/Enhanced split.
Platform matrix re-sectioned and decision flowchart updated.
README rewritten around the two-product-line framing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ios/README.md

@@ -1,8 +1,18 @@
-# SilverMetal iOS
+# SilverMetal Enhanced — iOS
 
-**Status**: Phase 4 (planning, post-Windows v1)
+**Status**: Phase 3I (planning, post-Linux v1)
 
-Tier D — profile-layer only. Weakest tier in the family; labelled as such. We cannot modify iOS; we ship MDM profiles, App Store apps, and a setup guide.
+🛡️ **SilverMetal Enhanced product line** — we harden iOS in place. We cannot modify iOS itself.
+
+Tier D — profile-layer only. Weakest tier in the family; labelled as such. We ship MDM profiles, App Store apps, and a setup guide.
+
+## Supersedes SilverApple
+
+This flavour replaces the earlier prototype [`SilverLABS/SilverApple`](https://git.silverlabs.uk/SilverLABS/SilverApple) ("Privacy-first iOS hardening suite"). Per Phase 3I.1 of the roadmap:
+
+- Inventory SilverApple's existing artefacts (MDM enrolment flow, SilverVPN onboarding, CalDAV/CardDAV setup)
+- Migrate any reusable parts into this directory
+- Archive the SilverApple repo on Gitea once migration is complete
 
 ## Scope (v1)
 
@@ -14,7 +24,7 @@ Tier D — profile-layer only. Weakest tier in the family; labelled as such. We
   - Default-app changes where iOS 18+ allows (Browser, Mail, etc.)
 - Stack ports via App Store:
   - SilverBrowser (subject to Apple WebKit constraints — fall back to a hardened-defaults wrapper if pure custom engine is forbidden)
-  - SilverVPN (NetworkExtension API)
+  - SilverVPN — already exists as a MAUI-based App Store candidate via [`SilverLABS/SilverVPN`](https://git.silverlabs.uk/SilverLABS/SilverVPN)
   - SilverSync (file/contact/calendar/photos providers)
   - SilverChat (post-v1.1)
   - SilverKeys (post-v1.1)
@@ -32,13 +42,14 @@ Tier D — profile-layer only. Weakest tier in the family; labelled as such. We
 
 ## Directory layout
 
-To be populated in Phase 4:
+To be populated in Phase 3I:
 
 ```
 ios/
-├── profile/         # .mobileconfig sources, signing
-├── stack/           # iOS-specific Stack app builds (Xcode projects)
-└── docs/            # setup guide, recommended apps, threat-tier disclaimer
+├── profile/           # .mobileconfig sources, signing
+├── stack/             # iOS-specific Stack app builds (Xcode projects)
+├── from-silverapple/  # migrated artefacts from the deprecated SilverApple repo
+└── docs/              # setup guide, recommended apps, threat-tier disclaimer
 ```
 
 ## Verification gates