fix: use global Filecoin proof parameter cache

.github/workflows/ci_run.yml

@@ -286,12 +286,12 @@ jobs:
     # Download and extract Filecoin proof parameters from S3
     - name: "EXEC: {Download proof parameters from S3}, independent"
       run: |
-        mkdir -p ~/.foc-devnet/docker/volumes/cache/filecoin-proof-parameters/
+        mkdir -p /var/tmp/filecoin-proof-parameters/
         curl -L https://fil-proof-params-2k-cache.s3.us-east-2.amazonaws.com/filecoin-proof-params-2k.tar -o /tmp/filecoin-proof-params-2k.tar
-        tar -xf /tmp/filecoin-proof-params-2k.tar -C ~/.foc-devnet/docker/volumes/cache/filecoin-proof-parameters/
+        tar -xf /tmp/filecoin-proof-params-2k.tar -C /var/tmp/filecoin-proof-parameters/
         rm /tmp/filecoin-proof-params-2k.tar
-        ls -lath ~/.foc-devnet/docker/volumes/cache/filecoin-proof-parameters/
-        PROOF_PARAMS_HASH=$(find ~/.foc-devnet/docker/volumes/cache/filecoin-proof-parameters -type f -exec sha256sum {} \; | cut -d' ' -f1 | sort | sha256sum | cut -d' ' -f1)
+        ls -lath /var/tmp/filecoin-proof-parameters/
+        PROOF_PARAMS_HASH=$(find /var/tmp/filecoin-proof-parameters -type f -exec sha256sum {} \; | cut -d' ' -f1 | sort | sha256sum | cut -d' ' -f1)
         echo "Downloaded proof parameters with hash: $PROOF_PARAMS_HASH"
 
     # Verify cluster is running correctly

README_ADVANCED.md

@@ -39,7 +39,7 @@ foc-devnet init [OPTIONS]
 - `--lotus <SOURCE>` - Lotus source location
 - `--filecoin-services <SOURCE>` - Filecoin Services source location
 - `--pdp <SOURCE>` - PDP source location. If omitted, uses the PDP submodule bundled with Filecoin Services.
-- `--proof-params-dir <PATH>` - Local proof params directory
+- `--proof-params-dir <PATH>` - Local proof params directory to copy into the global cache at `/var/tmp/filecoin-proof-parameters`
 - `--rand` - Use random mnemonic instead of deterministic one. Use this for unique test scenarios.
 
 **Source Format:**
@@ -359,6 +359,15 @@ $FOC_DEVNET_BASEDIR/
 └── tmp/
 ```
 
+Filecoin proof parameters are not stored under `FOC_DEVNET_BASEDIR`. They use the standard global host cache at `/var/tmp/filecoin-proof-parameters`, which is bind-mounted into Lotus, lotus-miner, and Curio containers at the same path.
+
+To reuse parameters from an older foc-devnet-private cache, copy them manually before starting:
+
+```bash
+mkdir -p /var/tmp/filecoin-proof-parameters
+cp -R ~/.foc-devnet/docker/volumes/cache/filecoin-proof-parameters/. /var/tmp/filecoin-proof-parameters/
+```
+
 ---
 
 ## Directory Structure
@@ -374,8 +383,7 @@ $FOC_DEVNET_BASEDIR/
 │   └── multicall3/                  # Multicall3 contracts
 ├── docker/
 │   └── volumes/
-│       ├── cache/                   # Shared cache (proof params, etc.)
-│       │   └── filecoin-proof-parameters/
+│       ├── cache/                   # Shared foc-devnet build/cache data
 │       └── run-specific/            # Run-isolated volumes
 │           └── <run-id>/            # Each run has its own volumes
 │               ├── lotus-data/      # Lotus blockchain data

src/commands/init/artifacts.rs

@@ -29,7 +29,7 @@ pub fn stage_artifacts(proof_params_dir: Option<String>) -> Result<(), Box<dyn s
     Ok(())
 }
 
-/// Copy filecoin-proof-params from a local directory.
+/// Copy filecoin-proof-params from a local directory into the global cache.
 ///
 /// This function copies proof parameters from a local directory instead of downloading them.
 ///
@@ -58,6 +58,14 @@ fn copy_proof_params_from_local(params_path: &str) -> Result<(), Box<dyn std::er
     // Create destination directory
     fs::create_dir_all(&dest_path)?;
 
+    if params_path.canonicalize()? == dest_path.canonicalize()? {
+        info!(
+            "Proof parameters already use the global cache: {}",
+            dest_path.display()
+        );
+        return Ok(());
+    }
+
     // Copy all files from source to destination
     let pb = ProgressBar::new_spinner();
     pb.set_style(