Run new CI gates through Nix

.forgejo/workflows/ci-gates.yml

@@ -79,22 +79,16 @@ jobs:
         run: |
           set -euo pipefail
           cd .repo
-          if [[ -f "$HOME/.cargo/env" ]]; then
-            . "$HOME/.cargo/env"
-          fi
-          cargo test -p ec-node publisher_proof
-          cargo test -p ec-node archive_convergence
+          nix develop --accept-flake-config -c cargo test -p ec-node publisher_proof
+          nix develop --accept-flake-config -c cargo test -p ec-node archive_convergence
 
       - name: Distributed simulation gates
         shell: bash
         run: |
           set -euo pipefail
           cd .repo
-          if [[ -f "$HOME/.cargo/env" ]]; then
-            . "$HOME/.cargo/env"
-          fi
-          cargo test -p ec-node sim_system_
-          cargo run -p ec-node -- sim-system \
+          nix develop --accept-flake-config -c cargo test -p ec-node sim_system_
+          nix develop --accept-flake-config -c cargo run -p ec-node -- sim-system \
             --fault-profile foundationdb \
             --seed 1 \
             --iterations 1024 \

evolution/proposals/ECP-0123-instant-station-guide-and-player-warmup.md

@@ -61,3 +61,5 @@ The workflow ECP gate starts at ECP-0120 because older proposals predate the cur
 The lint script uses ripgrep when available and falls back to GNU grep on the Forgejo runner.
 Cloudflare deployment decrypts the API token through the repo's agenix workflow and builds web
 assets through `scripts/build-web.sh` so local and runner build paths stay aligned.
+All Rust gates in Forgejo, including duplicate-publisher proof and simulation checks, enter through
+the same Nix dev shell so later CI additions do not silently depend on rustup state.