autosetup: instantiate $ templates against the contract's real methods

[jar-ben]

process_template_in_place blindly substituted $CONTRACT_NAME$ and emitted every entry a template declares. The extload template lists extsload/exttload/extSload overloads and return variants that come from different mixins (Uniswap Extsload/Exttload, Aave ExtSload), so any given contract implements only a subset. Emitting the rest produced two hard CVL typecheck failures:

• combineFunctions "un-mergeable signature …" — the template has two entries for the same signature with different returns (extsload(bytes32,uint256)→bytes32[] and →bytes; same for exttload(bytes32[])), which CVL can't merge.
• "Only public/external methods are DELETE-able" — a DELETE summary emitted for a method the contract doesn't have.

Fix

_filter_template_entries_to_contract keeps only the materialized methods{} entries matching a real method of the contract — by (name, parameter types, return type) — using methods_parser.get_methods_by_originating_contract. Consequences:

• same-signature/different-return duplicates collapse to the single variant the contract has (so both →bytes32[] and →bytes projects stay supported — the per-contract instantiation resolves it);
• entries for absent methods are dropped;
• non-matching receivers (wildcard _.) and all non-entry lines (CVL helper functions, comments) are preserved verbatim;
• if the contract's methods can't be determined, content is returned unchanged (no accidental over-pruning).

Why not just delete the →bytes variants / separate templates

The →bytes variants are original (pre-existing) and intended for real projects, so deleting them loses coverage. Separate templates don't help — the registry matches by name, so both would still apply. The discriminator is the return type, which only the contract's actual method carries; hence method-aware instantiation.

Validation

• tests/test_extload_template_filter.py (new, 4 cases): keep-only-matching, no-duplicate-signatures, keeps-bytes-variant-when-that's-what-the-contract-has (the two-return case), and unknown-methods-leaves-content-unchanged. Full summary unit suite green (23 passed).

Dependencies & follow-ups

• Stacked on PRs 1–4. Fixes a pre-existing template-instantiation flaw that PR 2 (adding extSload matching) exposed