Respect ModuleCache max size

[ndr-ds]

Motivation

ModuleCache::insert() never incremented total_size after inserting a new entry. It only decremented during
eviction in reduce_size_to(). This meant:

• total_size was permanently 0
• The eviction check if self.total_size + bytecode_size > self.max_size never triggered
• The cache grew unboundedly despite the 512 MiB limit
• reduce_size_to() would underflow on the subtraction self.total_size -= bytecode_size

Proposal

• Add self.total_size += bytecode_size after insertion, only when the key wasn't already present (to avoid
  double-counting on re-insertion of the same bytecode)
• Add an early return when a single bytecode exceeds max_size, which prevents an underflow in the self.max_size - bytecode_size computation passed to reduce_size_to()
• Add 4 unit tests covering: size tracking, eviction triggering, oversized rejection, and duplicate key handling

Test Plan

• CI + new tests pass

Release Plan

• These changes should be backported to the latest testnet branch, then
  • be released in a validator hotfix.

[ndr-ds]

• Respect ModuleCache max size #5441 👈 (View in Graphite)
• main

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[afck]

Is this equivalent? No need to put if the module is already in the cache?

Suggested change

	if self.modules.contains(&bytecode) {
	self.modules.put(bytecode, module);
	return;
	}
	if self.modules.promote(&bytecode) {
	return;
	}

[ndr-ds]

Good point, I need up upgrade the lru crate version for that though. Will do it