fix(build): strip unused vergen cargo/rustc features to reduce deps

VERGEN_CARGO_* and VERGEN_RUSTC_* env vars were emitted by build.rs
but never referenced in source. The cargo feature pulled in
cargo_metadata + derive_builder, adding unnecessary build-dep weight
and lockfile churn. Slim-glibc was 2% over the 5MiB bloat threshold.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: maxholman

Cargo.lock

@@ -21,6 +21,7 @@ mkdir -p "$RESULTS_DIR"
 cd "$ROOT_DIR"
 
 # --- Size thresholds (bytes) ---
+# DO NOT BUMP WITHOUT PERMISSION.
 # Updated: 2026-03-15, baseline: worktree-mcp-server
 # slim threshold = exactly 5MiB (5 * 1024 * 1024). Must stay "5MB slim".
 # default threshold = existing measured + ~1% headroom.

bench/check_bloat.sh

@@ -51,7 +51,7 @@ wallhackd = { path = "../daemon", default-features = false }
 zeroize = "1"
 
 [build-dependencies]
-vergen-gitcl = { version = "9.1", features = ["build", "cargo", "rustc"] }
+vergen-gitcl = { version = "9.1", features = ["build"] }
 
 [lints]
 workspace = true

crates/cli/Cargo.toml

@@ -1,4 +1,4 @@
-use vergen_gitcl::{BuildBuilder, CargoBuilder, Emitter, GitclBuilder, RustcBuilder};
+use vergen_gitcl::{BuildBuilder, Emitter, GitclBuilder};
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     // PROFILE is a standard Cargo build env var; emit it for use via env!() in source.
@@ -10,13 +10,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     Emitter::default()
         .add_instructions(&BuildBuilder::default().build_timestamp(true).build()?)?
         .add_instructions(&GitclBuilder::default().sha(true).dirty(true).build()?)?
-        .add_instructions(
-            &CargoBuilder::default()
-                .target_triple(true)
-                .features(true)
-                .build()?,
-        )?
-        .add_instructions(&RustcBuilder::default().semver(true).build()?)?
         .emit()?;
     Ok(())
 }

crates/cli/build.rs

@@ -16,7 +16,7 @@ wallhack-ipc = { path = "../ipc", features = ["vsock"] }
 wallhack-wire = { path = "../wire" }
 
 [build-dependencies]
-vergen-gitcl = { version = "9.1", features = ["build", "cargo"] }
+vergen-gitcl = { version = "9.1", features = ["build"] }
 
 [lints.rust]
 unsafe_code = "deny"

crates/mcp/Cargo.toml

@@ -1,4 +1,4 @@
-use vergen_gitcl::{BuildBuilder, CargoBuilder, Emitter, GitclBuilder};
+use vergen_gitcl::{BuildBuilder, Emitter, GitclBuilder};
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     println!(
@@ -8,7 +8,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     Emitter::default()
         .add_instructions(&BuildBuilder::default().build_timestamp(true).build()?)?
         .add_instructions(&GitclBuilder::default().sha(true).dirty(true).build()?)?
-        .add_instructions(&CargoBuilder::default().target_triple(true).build()?)?
         .emit()?;
     Ok(())
 }