chore(scaffold): initial SilverMetal program scaffold

Cross-platform privacy-hardening program. Two-layer product:
- SilverLABS Application Stack (cross-platform spine)
- Platform Hardening Profiles (per-OS, tier-honest)

Platforms: Linux (Debian/Kicksecure), Android (Pixel/Samsung/Moto/generic),
Windows (LTSC IoT), macOS (profile), iOS (MDM profile). Each flavour has
both a preflashed hardware SKU path and a self-apply "harden your existing
device" path.

Includes umbrella docs (README + threat-model, design-principles,
platform-matrix, roadmap, trust-model), per-platform and per-stack-
component README stubs, .gitignore, LICENSE.

Linux v1 ships first; Stack v1 = Browser + VPN + Sync.

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

shared/branding/README.md

@@ -0,0 +1,14 @@
+# Branding
+
+Logos, colour tokens, design system. To be populated when the brand identity is finalised.
+
+## Naming convention
+
+- Family brand: **SilverMetal**
+- Per-platform: `SilverMetal Linux`, `SilverMetal Droid`, `SilverMetal Windows`, `SilverMetal macOS`, `SilverMetal iOS`
+- Stack apps: `SilverBrowser`, `SilverVPN`, `SilverSync`, `SilverChat`, `SilverDuress`, `SilverKeys`
+- Per-Android-tier suffix: `SilverMetal Droid Flagship` (Pixel), `Galaxy` (Samsung), `Moto` (Motorola), `Profile` (generic)
+
+## Visual identity
+
+To be defined. Consistent with the broader SilverLABS visual language (dark professional, cyan accent — see SilverLABS frontend prompt) but with its own distinguishable mark.