chore(deployer): remove OPCMv1 migration, upgrade, and dev feature code

[smartcontracts]

Summary

Remove all remaining OPCMv1 code from op-deployer and related packages. Follow-up to #19795 (Solidity-side removal) and #19919 (mechanical struct/compat cleanup).

• Delete v1 migration code: MigrateInputV1, GameParameters, OPChainConfig structs, EncodedMigrateInputV1(), v1 branch in MigrateCLI(), v1-specific CLI flags (ProposerFlag, ChallengerFlag, DisputeAbsolutePrestate{Cannon,CannonKona}Flag, etc.)
• Delete v1 add-game-type command: manage/add_game_type.go, opcm/add_game_type.go and tests (subsumed by add-game-type-v2 / upgrade)
• Delete v1 upgrade fallback: embedded.OPChainConfig, EncodedOpChainConfigs(), v1 branch in Upgrade()
• Delete deprecated output fields: DeployImplementationsOutput.Opcm and 5 other v1 inner contract fields; corresponding Solidity DeployImplementations.s.sol Output struct fields
• Delete dead struct fields: OpcmGameTypeAdderImpl, OpcmDeployerImpl, OpcmUpgraderImpl from ImplementationsContracts; Opcm from interopgen.Implementations
• Delete IsVersionAtLeast() — sole caller removed
• Simplify tests: Remove v1/v2 branching in integration tests, delete dead v1 test functions

22 files changed, +168 / -2,111 lines (net -1,943)

Test plan

• go build ./... passes
• go vet ./op-deployer/... ./op-chain-ops/... passes
• CI passes

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.4%. Comparing base (88cd69c) to head (a110ff5).
⚠️ Report is 1 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #20024      +/-   ##
===========================================
+ Coverage     11.7%    79.4%   +67.7%     
===========================================
  Files          676      138     -538     
  Lines        71016     6699   -64317     
===========================================
- Hits          8322     5325    -2997     
+ Misses       62550     1374   -61176     
+ Partials       144        0     -144     

Flag	Coverage Δ
cannon-go-tests-64	?
contracts-bedrock-tests	79.4% <ø> (ø)
unit	?

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see 538 files with indirect coverage changes

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