`@wraith-protocol/sdk-solid` companion

[truthixify]

Tier: M (2-4 days) | Type: feature

Context. With sdk-react, sdk-vue, and sdk-svelte all reaching parity in Wave 7, Solid is the remaining top-4 framework without a companion. Solid's fine-grained reactivity model doesn't map cleanly onto the React useState shape, so a translated port is worth its own package rather than a wrapper.

Scope.

• New workspace package packages/sdk-solid/ following the sdk-vue layout.
• Ports of the sdk-react hook set as Solid primitives: createStealthKeys, createScanner, createMetaAddress, createActivity.
• Signals, not effects, for reactive values; cleanup via onCleanup.
• Example: examples/stellar-solid-receive/ (Vite + SolidStart).

Acceptance.

• Primitive shape matches sdk-react's per-hook contract where possible
• @testing-library/solid covers primitive reactivity
• Example dev server renders and scans against a canned announcement fixture
• Package tree-shakes to only the primitives the app imports

Files. packages/sdk-solid/ (new), packages/sdk-solid/src/primitives/ (new), examples/stellar-solid-receive/ (new).