Variable WASM_PANIC_STASH_KEY`Const`

WASM_PANIC_STASH_KEY: "__ifclite_wasm_panic"

Kept in lockstep with PANIC_STASH_KEY in rust/wasm-bindings/src/utils.rs and WASM_PANIC_STASH_KEY in apps/viewer/src/lib/analytics-scrub.ts.