build(upgradeable): make the upgradeable transpile pipeline work on the Tron fork

[luiz-lvj]

What

Adapts the upgradeable transpilation tooling (copied verbatim from openzeppelin-contracts)
so it actually runs on this fork and produces a compilable @openzeppelin/tron-contracts-upgradeable
from our contracts/. This is the source-repo half of the tron-contracts → tron-contracts-upgradeable
mirror, modeled on openzeppelin-contracts → openzeppelin-contracts-upgradeable.

Out of scope (separate follow-ups): the upgradeable.yml CI wiring + GH_TOKEN_UPGRADEABLE
secret, npm publishing (release-upgradeable.yml), and getting the transpiled test suite green.

Changes

scripts/upgradeable/transpile.sh

• Compile step → single stock-solc pass (rm -rf artifacts cache + SKIP_EXPOSED=1 hardhat compile --network hardhat)
  instead of npm run compile. Our default compile is tron:compile-batches, which splits the
  corpus into ~13 build-info files to dodge the tron-solc wasm ceiling — but the transpiler requires
  exactly one. Under --network hardhat the config routes to stock solc (no wasm limit → one
  this is VM-agnostic and correct.
• Replaced npm run clean (no such script here → would error) with rm -rf artifacts cache.
• Dropped -q '@openzeppelin/': our contracts import via relative paths, so the peer prefix matched
  nothing (no-op). We transpile self-contained.
• Dropped the alias/*.sol copy: those stubs re-export Initializable/UUPSUpgradeable from a
  @openzeppelin/contracts peer; in a self-contained build they'd overwrite the real transpiled files.

scripts/upgradeable/transpile-onto.sh

• Renamed the provenance submodule lib/openzeppelin-contracts → lib/tron-contracts (it pins the
  exact source commit each transpile was generated from).

scripts/upgradeable/upgradeable.patch (rebuilt: 390 → 212 lines)

• Kept the two source-correctness hunks: EIP712.sol (drops the ShortStrings immutable cache —
  also resolves a ShortString import the transpiler over-renames) and ReentrancyGuard.sol
  (explicit ERC-7201 struct, no constructor).
• Kept the EIP712.test.js hunk (drops a sub-test that can't pass on the upgradeable variant).
• Fork-adapted contracts/package.json (name → @openzeppelin/tron-contracts-upgradeable, repo URL).
• Dropped OZ-only hunks that don't apply here: the absent AccountEIP7702* tests, and cosmetic
  README/issue-template/root-package.json/remappings edits.

Design note: self-contained vs peer

OZ runs the transpiler in "peer" mode (-q), pulling stateless code (interfaces, libraries,
Initializable) from the published @openzeppelin/contracts package + a submodule. Our contracts
use relative imports, so that prefix matches nothing here — this transpiles self-contained:
every contract, including interfaces/libraries, is emitted with the Upgradeable suffix
(ITRC20Upgradeable, MathUpgradeable), with no dependency on a peer package. Simpler for a fork;
peer-parity can be a later refinement.