chore: bump version to 0.7.0 + download page updates

Bumps:
- crates/{core,cli,tauri-app}/Cargo.toml: 0.6.2 → 0.7.0
- crates/tauri-app/tauri.conf.json: 0.6.2 → 0.7.0
- gen/android/app/tauri.properties: versionName 0.7.0, versionCode 7000

website/download.html: v0.7.0 promoted to top with FoF release notes;
v0.6.2 retained in archive section. Wire-additive notice + link to
design.html#fof for full architecture.

No -beta suffix this cycle: no users on prior version means no need
for the beta carve-out. Will resume beta convention when there are
real users to migrate.

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

Cargo.lock

@@ -2732,7 +2732,7 @@ checksum = "92ecc6618181def0457392ccd0ee51198e065e016d1d527a7ac1b6dc7c1f09d2"
 
 [[package]]
 name = "itsgoin-cli"
-version = "0.6.2"
+version = "0.7.0"
 dependencies = [
  "anyhow",
  "hex",
@@ -2744,7 +2744,7 @@ dependencies = [
 
 [[package]]
 name = "itsgoin-core"
-version = "0.6.2"
+version = "0.7.0"
 dependencies = [
  "anyhow",
  "base64 0.22.1",
@@ -2767,7 +2767,7 @@ dependencies = [
 
 [[package]]
 name = "itsgoin-desktop"
-version = "0.6.2"
+version = "0.7.0"
 dependencies = [
  "anyhow",
  "base64 0.22.1",