Two independent cross-PR collisions red on main (slice 8/8):
1. fd4f756492 (salvaged from stale #54514) added an early 'drop U+FFFC
placeholder' return at the top of _dispatch_inbound — written before
the deferred-wait handler (6b91b50c6e/afab7ed46e) existed further
down the same function. The early return shadowed it: _pending_fffc
never populated, no attachment-timeout tracking, 4 tests red. Remove
the duplicate block; the deferred handler already drops the
placeholder AND tracks/cancels/warns.
2. 9cf2046081 tightened sidecar_deps_installed() to require
node_modules/spectrum-ts, but test_runtime_record's _patch_spawn
fixture still created only bare node_modules/ — 2 tests red. Mirror
a real completed install.
tests/plugins/platforms/photon: 164/164 after; 158/164 before.
ceaa7880ee