[nix] add some missing devshell dependencies

flake.nix

@@ -97,6 +97,31 @@
           # nixpkgs bump can't silently drift the devshell's tool versions.
           lowrisc-nix.packages.${system}.verilator_5_048
           lowrisc-nix.packages.${system}.verible_0_0_4080
+          # Bazel pinned to match .bazelversion (8.7.0). With this on PATH,
+          # ./bazelisk.sh uses it directly instead of downloading Bazel over the
+          # network, so the build is hermetic and reproducible. Keep this version
+          # in sync with .bazelversion (bazelisk falls back to downloading if
+          # they ever diverge).
+          lowrisc-nix.packages.${system}.bazel_8_7_0
+          # OpenSSL headers + libcrypto for the AES DPI model (hw/ip/aes/model:
+          # crypto.c includes <openssl/*.h> and links -lcrypto).
+          pkgs.openssl
+          # srec_cat, invoked by rules/opentitan/transform.bzl to convert build
+          # artifacts (e.g. SW images -> SREC/VMEM).
+          pkgs.srecord
+          # xxd, invoked by rules/opentitan/cc.bzl (`... | xxd -r -p`) during the
+          # SW image build.
+          pkgs.unixtools.xxd
+          # lcov/genhtml, used by util/coverage to collect and render SW (C/C++)
+          # coverage.
+          pkgs.lcov
+          # Hardware-interaction libs/tools used by opentitantool and
+          # FPGA/chip bring-up (JTAG, USB, smartcard, serial xmodem/zmodem).
+          pkgs.libftdi1
+          pkgs.libusb1
+          pkgs.pcsclite
+          pkgs.dfu-util
+          pkgs.lrzsz
         ];
       };
     in {
@@ -107,6 +132,15 @@
         default = eda;
       };
 
+      # `nix run .#eda` drops into the EDA sandbox in your $SHELL; with args,
+      # `nix run .#eda -- <cmd> <args>` execs them inside the sandbox (argv is
+      # passed through directly, so use e.g. `-- bash -c '...'` for a shell
+      # snippet). mkEdaShell exposes the ready-made flake-app payload as `eda.app`.
+      apps = {
+        eda = eda.app;
+        default = eda.app;
+      };
+
       formatter = pkgs.alejandra;
     });
 }