fix(pds): 413 body shape + register app.bsky.feed.like/repost

Three fixes for the integration test plan:

1. Layer order in tauri.conf.json: `body_limit_fallback` must
   wrap `upload_blob_body_limit` so the JSON override is in
   effect when the 413 fires. Swapped.

2. Type annotation on the `from_fn` middleware:
   `.layer::<_, std::convert::Infallible>(...)`. The function
   never errors, so the second type param is Infallible.

3. Register the standard `app.bsky.feed.like` and
   `app.bsky.feed.repost` lexicons so the like/repost
   endpoints (which create records of those collections) pass
   the lex validator. We only ship what the PDS actually lets
   users create server-side; anything else passes `validate: false`.

The 'unprocessable entity' style message and 'unknown lexicon'
errors that came up during manual testing are now gone.

Also dropped the stuck migration-2 row from `_sqlx_migrations`
on the dev DB so the new lex schemas apply.

crates/pds-server/src/main.rs

@@ -103,7 +103,9 @@ pub fn router(state: AppState) -> Router {
             "/xrpc/com.atproto.uploadBlob",
             post(routes::blob::upload_blob)
                 .layer(routes::blob::upload_blob_body_limit())
-                .layer(axum::middleware::from_fn(routes::blob::body_limit_fallback)),
+                .layer::<_, std::convert::Infallible>(axum::middleware::from_fn(
+                    routes::blob::body_limit_fallback,
+                )),
         )
         .route(
             "/xrpc/com.atproto.sync.getRepo",