fix: address review suggestions from #1 (single-branch clone, HooksManager pinning)

.upstreamer/scripts/verify.sh

@@ -59,8 +59,11 @@ if command -v go >/dev/null 2>&1; then
 fi
 echo
 
-# Hooks and versioned state are the 0.8.0 parity floor. Named loosely because
-# the Go equivalents may not match TS spelling exactly; the eval checks behavior.
+# Hooks and versioned state are the 0.8.0 parity floor. The 0.8.0 port chose
+# the upstream spelling `HooksManager` verbatim, so this check pins that exact
+# name; the contract's required-API list is the source of truth. If a future
+# port renames it, that is a contract change — update the contract's naming map
+# and this check together, not just the code.
 echo "-- 0.8.0 parity surface present"
 grep -rqE '\bHooksManager\b' --include='*.go' . 2>/dev/null \
   && pass "hooks manager present" \

.upstreamer/upstreamer.md

@@ -80,7 +80,9 @@ Stop conditions:
 - `StepCountIs`, `HasToolCall`, `MaxTokensUsed`, `MaxCost`, `FinishReasonIs`
 
 Lifecycle hooks (upstream #7, #67 — the 0.8.0 headline):
-- A `HooksManager` equivalent with options, hook name constants, hook
+- A `HooksManager` type — pinned to the upstream spelling, which is already
+  idiomatic Go (the 0.8.0 port adopted it verbatim; `verify.sh` checks the
+  exact name) — with options, hook name constants, hook
   definition/entry/handler/registry types, tool matchers, `PostModelCall`
   telemetry, `SessionEnd` usage totals
 - Session-id threading per emit so a shared manager is concurrency-safe

scripts/upstream

@@ -124,11 +124,21 @@ if [ -d "$upstream_dir/.git" ]; then
   git -C "$upstream_dir" fetch --tags --force origin
 else
   rm -rf "$upstream_dir"
-  git clone "$upstream_url" "$upstream_dir"
+  # --single-branch: CI recreates this clone every run, and fetching the whole
+  # ref namespace roughly doubles clone time for nothing — the script targets
+  # origin/HEAD or a release tag (reachable from the default branch, so still
+  # fetched). Refs outside that (e.g. a manual run against a feature branch)
+  # are handled by the fallback fetch below.
+  git clone --single-branch "$upstream_url" "$upstream_dir"
 fi
 
 if [ -n "$ref" ]; then
-  target_commit="$(git -C "$upstream_dir" rev-parse "$ref^{commit}")"
+  # --end-of-options / --: a ref value starting with "-" must not be parsed as
+  # an option (CI refs always start with "@", but manual runs take anything).
+  if ! target_commit="$(git -C "$upstream_dir" rev-parse --quiet --verify --end-of-options "$ref^{commit}")"; then
+    git -C "$upstream_dir" fetch origin -- "$ref"
+    target_commit="$(git -C "$upstream_dir" rev-parse FETCH_HEAD^{commit})"
+  fi
 else
   target_commit="$(git -C "$upstream_dir" rev-parse origin/HEAD 2>/dev/null || git -C "$upstream_dir" rev-parse origin/main)"
 fi