feat(rust): unify workspaces

[theochap]

Summary

• Merges all separate Rust workspaces (alloy-op-evm, alloy-op-hardforks, kona, op-alloy, op-reth) into a single unified workspace under rust/
• Removes per-workspace Cargo.lock, Cargo.toml, deny.toml, rustfmt.toml, and clippy.toml files in favor of shared root-level configs
• Updates CI configuration (.circleci/) to point to the new workspace structure

Test plan

• CI passes with the new unified workspace layout
• All Rust crates build successfully under rust/
• Existing tests pass in the merged workspace

🤖 Generated with Claude Code

[wiz-inc-a178a98b5d]

Wiz Scan Summary

Scanner	Findings
Vulnerabilities	-
Sensitive Data	-
Secrets	-
IaC Misconfigurations	1
SAST Findings	-
Software Management Findings	-
Total	1

View scan details in Wiz

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[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 60 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.7%. Comparing base (db87881) to head (356de36).
⚠️ Report is 2 commits behind head on develop.

Files with missing lines	Patch %	Lines
rust/alloy-op-evm/src/block/canyon.rs	63.1%	7 Missing ⚠️
rust/kona/bin/host/src/interop/handler.rs	0.0%	6 Missing ⚠️
rust/kona/crates/node/engine/src/sync/mod.rs	0.0%	6 Missing ⚠️
...tes/node/engine/src/task_queue/tasks/build/task.rs	0.0%	6 Missing ⚠️
rust/kona/bin/client/src/interop/transition.rs	0.0%	5 Missing ⚠️
...na/crates/node/engine/src/task_queue/tasks/task.rs	0.0%	4 Missing ⚠️
rust/kona/crates/node/peers/src/record.rs	0.0%	4 Missing ⚠️
rust/kona/crates/node/disc/src/driver.rs	0.0%	3 Missing ⚠️
rust/kona/bin/host/src/server.rs	0.0%	2 Missing ⚠️
rust/kona/bin/host/src/single/handler.rs	0.0%	2 Missing ⚠️
... and 12 more

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #19034      +/-   ##
===========================================
- Coverage     76.3%    75.7%    -0.7%     
===========================================
  Files          188      700     +512     
  Lines        10946    71986   +61040     
===========================================
+ Hits          8360    54495   +46135     
- Misses        2440    17347   +14907     
+ Partials       146      144       -2     

Flag	Coverage Δ
cannon-go-tests-64	66.4% <ø> (-0.9%)	⬇️
contracts-bedrock-tests	81.6% <ø> (-0.1%)	⬇️
unit	75.6% <50.0%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
rust/alloy-op-evm/src/block/receipt_builder.rs	86.9% <ø> (ø)
rust/alloy-op-evm/src/lib.rs	90.8% <100.0%> (ø)
rust/alloy-op-hardforks/src/lib.rs	93.2% <100.0%> (ø)
rust/kona/bin/client/src/fpvm_evm/factory.rs	0.0% <ø> (ø)
...in/client/src/fpvm_evm/precompiles/bls12_g1_add.rs	100.0% <ø> (ø)
...in/client/src/fpvm_evm/precompiles/bls12_g1_msm.rs	100.0% <ø> (ø)
...in/client/src/fpvm_evm/precompiles/bls12_g2_add.rs	100.0% <ø> (ø)
...in/client/src/fpvm_evm/precompiles/bls12_g2_msm.rs	100.0% <ø> (ø)
...in/client/src/fpvm_evm/precompiles/bls12_map_fp.rs	100.0% <ø> (ø)
...n/client/src/fpvm_evm/precompiles/bls12_map_fp2.rs	100.0% <ø> (ø)
... and 105 more

... and 403 files with indirect coverage changes

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[sebastianst]

A few nits before I approve. Still reviewing Cargo.toml.

For reference how I reviewed it: I locally checked out the branch, then restored all **/src/** dirs from the base commit, then let Claude fix builds, ran clippy fix, then reviewed the remaining diff. This showed only code-equivalent changes of clippy warnings. I then also manually reviewed the