fix: make bash scripts portable to bash 3.2 (macOS system /bin/bash)

Adding macos-latest to the CI matrix surfaced two pre-existing bash 3.2
incompatibilities (macOS ships bash 3.2 as /bin/bash):

1. update-agent-context.sh embedded Python heredocs inside $(...) command
   substitution. bash 3.2 mis-parses an apostrophe in a heredoc body
   nested in $(...), failing with "unexpected EOF while looking for
   matching `''". Removed the apostrophes from the affected $()-nested
   heredoc body and documented the constraint to prevent regressions.

2. create-new-feature-branch.sh and create-new-feature.sh used the
   bash 4+ ${word^^} uppercase parameter expansion, which errors as a
   "bad substitution" on bash 3.2 and caused short uppercase acronyms
   (e.g. "GO") to be dropped from derived branch names. Replaced with a
   portable `tr '[:lower:]' '[:upper:]'` pipeline.

Verified the full test suite passes under bash 3.2.57 and shellcheck
(--severity=error) is clean.

Assisted-by: GitHub Copilot (model: Claude Opus 4.8, autonomous)
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: mnriem

extensions/agent-context/scripts/bash/update-agent-context.sh

@@ -59,6 +59,13 @@ case "$(uname -s 2>/dev/null || true)" in
 esac
 
 # Parse extension config once; emit context files as JSON, followed by marker strings.
+#
+# NOTE (bash 3.2 / macOS portability): the embedded Python heredocs below run
+# inside $(...) command substitution. bash 3.2 (the system /bin/bash on macOS)
+# mis-parses a single-quote/apostrophe in a heredoc body nested in $(...),
+# failing with "unexpected EOF while looking for matching `''". Keep these
+# $(...)-nested heredoc bodies free of apostrophes (use double quotes in Python
+# string literals and avoid contractions in comments).
 if ! _raw_opts="$("$_python" - "$EXT_CONFIG" "$_case_insensitive_context_files" "$PROJECT_ROOT" <<'PY'
 import json
 import sys
@@ -115,7 +122,8 @@ if not context_files:
 if not context_files:
     # Self-seed: the agent-context extension owns its lifecycle, so when its
     # own config declares no target it derives one from the active integration
-    # recorded in init-options.json, using the extension's OWN bundled mapping
+    # recorded in init-options.json, using the OWN bundled mapping of the
+    # agent-context extension
     # (agent-context-defaults.json). This is independent of the Specify CLI by
     # design — nothing here imports specify_cli.
     project_root = sys.argv[3] if len(sys.argv) > 3 else "."
@@ -144,15 +152,15 @@ if not context_files:
         except Exception:
             print(
                 "agent-context: unable to read %s; cannot self-seed the context "
-                "file. Set 'context_file' in the extension config." % defaults_path,
+                "file. Set context_file in the extension config." % defaults_path,
                 file=sys.stderr,
             )
             mapping = {}
         add_context_file(mapping.get(integration_key, "") or "")
         if not context_files:
             print(
                 "agent-context: no default context file is known for integration "
-                "'%s'. Set 'context_file' in the extension config to choose one."
+                "%s. Set context_file in the extension config to choose one."
                 % integration_key,
                 file=sys.stderr,
             )

extensions/git/scripts/bash/create-new-feature-branch.sh

@@ -288,7 +288,7 @@ generate_branch_name() {
         if ! echo "$word" | grep -qiE "$stop_words"; then
             if [ ${#word} -ge 3 ]; then
                 meaningful_words+=("$word")
-            elif echo "$description" | grep -qw -- "${word^^}"; then
+            elif echo "$description" | grep -qw -- "$(printf '%s' "$word" | tr '[:lower:]' '[:upper:]')"; then
                 meaningful_words+=("$word")
             fi
         fi

scripts/bash/create-new-feature.sh

@@ -152,7 +152,7 @@ generate_branch_name() {
         if ! echo "$word" | grep -qiE "$stop_words"; then
             if [ ${#word} -ge 3 ]; then
                 meaningful_words+=("$word")
-            elif echo "$description" | grep -q "\b${word^^}\b"; then
+            elif echo "$description" | grep -q "\b$(printf '%s' "$word" | tr '[:lower:]' '[:upper:]')\b"; then
                 # Keep short words if they appear as uppercase in original (likely acronyms)
                 meaningful_words+=("$word")
             fi