refactor: extract shared helper for duplicated logic (#46) (#55)

* refactor: extract StorageClientBase to dedupe StorageClient and StorageMobile (#46)

Both StorageClient (with logger support) and StorageMobile (lightweight variant)
were ~420-line near-identical classes. Extract all shared WalletStorageProvider
method implementations and entity-validation helpers into StorageClientBase.
Each subclass now only implements the rpcCall method that differs between them.

Partial fix for #46.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* chore: update pnpm-lock.yaml to include tsx in ts-p2p devDependencies

Fixes frozen-lockfile CI failure introduced in c4db522 which added tsx
to ts-p2p devDependencies without regenerating the lockfile.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* refactor: extract entity validation helpers to remove cross-file duplication

Extract validateDate, validateEntity, and validateEntities from both
StorageClientBase and StorageServer into a shared entityValidationHelpers.ts.
Both classes now delegate to the standalone functions, removing the duplicate
implementation that SonarCloud flagged between the two files.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* refactor: extract validateSyncChunkEntities helper to remove getSyncChunk duplication

Both StorageClientBase.getSyncChunk and StorageServer's processSyncChunk case
had the same 13-line SyncChunk entity-validation block. Extract it into
validateSyncChunkEntities() in entityValidationHelpers.ts and replace both sites.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix: add Array.isArray guard in validateEntities to prevent loop-bound injection

CodeQL flags js/loop-bound-injection when iterating with .length on a
user-controlled value. Guard with Array.isArray() so non-array inputs
(e.g. JSON objects with a spoofed .length) are returned unchanged.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sirdeggen