fix(sqlite-store): reject zero partial_blockchain_nodes.id instead of panicking

[ygd58]

Searched for existing issues/PRs (NonZeroUsize, InOrderIndex, partial_blockchain_nodes, parse_partial_blockchain_nodes) before writing this - #1691 is the only related hit and it's a different concern (32-bit usize limiting the max representable index in WASM builds, not this panic).

Bug

parse_partial_blockchain_nodes called NonZeroUsize::new(id).unwrap() on a u64 id column read directly from the local sqlite database. InOrderIndex::new requires a NonZeroUsize (from_leaf_pos's minimum output is 1 - pos * 2 - 1 with pos >= 1), so a stored id of 0 is never something the client's own write path produces - it can only come from a corrupted or externally-tampered-with local database, and would panic the client instead of surfacing an error.

Fix

Routes this through the function's existing Result<_, StoreError> instead, using the already-existing StoreError::ParsingError variant - no new error variant needed, and matches the pattern the two adjacent conversions in the same function already use (the id/usize::try_from and the node/Word::read_from_bytes both already return errors rather than panicking; this brings the third field in line).

Test plan

Added a direct unit test constructing a zero-id row and asserting the error, without needing the full store/connection test harness. Ran locally, not just CI:

cargo test -p miden-client-sqlite-store parse_partial_blockchain_nodes_rejects_zero_id -- --nocapture

1 passed. Also ran the full crate suite: 91 passed, 0 failed - no regressions.

[juan518munoz]

so a stored id of 0 is never something the client's own write path produces - it can only come from a corrupted or externally-tampered-with local database, and would panic the client instead of surfacing an error.

This is an edge case too far-fetched to consider handling by surfacing an error, the current unwrap is adequate, at most it could be expected with a more specific message, but the terminal would still throw that we tried to cast from zero in that specific line.