framework tools/git: strict value guards + provider-failure normalization family-wide (codex blockers on PR #1464)

- Value guards now reject option-like values: --anything always, and
  single-dash flag shapes (-h, -i). Previously -b --help consumed
  --help as the body and performed the write (codex example:
  issue-close -i --help proceeding to 'Closed GitHub issue #--help').
  Multi-char dash-leading text (-start of a list) stays a legal value.
- Every remaining direct provider exec (gh/tea/CMD arrays across
  issue-create/edit/assign/list/view, milestone-*, pr-create/edit,
  pr-close, issue-close/reopen) wrapped with rc capture and normalized
  to exit 1 with a stderr message — provider exit 2 no longer collides
  with the reserved usage-error status.
- All 16 usage-contract suites gained option-like and short-flag arms
  (16/16 green). Existing suites re-verified; test-pr-edit and
  test-issue-create-interactive-auth fail identically with these
  changes stashed (environment-coupled, not regressions; documented).

packages/mosaic/framework/tools/git/issue-list.sh

@@ -50,32 +50,32 @@ usage_error() {
 while [[ $# -gt 0 ]]; do
     case $1 in
         -s|--state)
-            [[ $# -ge 2 ]] || usage_error "option $1 requires a value"
+            [[ $# -ge 2 && "$2" != --* && ! "$2" =~ ^-[a-zA-Z]$ ]] || usage_error "option $1 requires a value (option-like values are rejected)"
             STATE="$2"
             shift 2
             ;;
         -l|--label)
-            [[ $# -ge 2 ]] || usage_error "option $1 requires a value"
+            [[ $# -ge 2 && "$2" != --* && ! "$2" =~ ^-[a-zA-Z]$ ]] || usage_error "option $1 requires a value (option-like values are rejected)"
             LABEL="$2"
             shift 2
             ;;
         -m|--milestone)
-            [[ $# -ge 2 ]] || usage_error "option $1 requires a value"
+            [[ $# -ge 2 && "$2" != --* && ! "$2" =~ ^-[a-zA-Z]$ ]] || usage_error "option $1 requires a value (option-like values are rejected)"
             MILESTONE="$2"
             shift 2
             ;;
         -a|--assignee)
-            [[ $# -ge 2 ]] || usage_error "option $1 requires a value"
+            [[ $# -ge 2 && "$2" != --* && ! "$2" =~ ^-[a-zA-Z]$ ]] || usage_error "option $1 requires a value (option-like values are rejected)"
             ASSIGNEE="$2"
             shift 2
             ;;
         -n|--limit)
-            [[ $# -ge 2 ]] || usage_error "option $1 requires a value"
+            [[ $# -ge 2 && "$2" != --* && ! "$2" =~ ^-[a-zA-Z]$ ]] || usage_error "option $1 requires a value (option-like values are rejected)"
             LIMIT="$2"
             shift 2
             ;;
         -r|--repo)
-            [[ $# -ge 2 ]] || usage_error "option $1 requires a value"
+            [[ $# -ge 2 && "$2" != --* && ! "$2" =~ ^-[a-zA-Z]$ ]] || usage_error "option $1 requires a value (option-like values are rejected)"
             REPO_OVERRIDE="$2"
             shift 2
             ;;
@@ -108,7 +108,9 @@ case "$PLATFORM" in
         [[ -n "$LABEL" ]] && CMD+=(--label "$LABEL")
         [[ -n "$MILESTONE" ]] && CMD+=(--milestone "$MILESTONE")
         [[ -n "$ASSIGNEE" ]] && CMD+=(--assignee "$ASSIGNEE")
-        "${CMD[@]}"
+        prov_rc=0
+        "${CMD[@]}" || prov_rc=$?
+        [[ "$prov_rc" -eq 0 ]] || { echo "Error: provider command failed (exit ${prov_rc}; provider failure, not a usage error)" >&2; exit 1; }
         ;;
     gitea)
         if [[ -n "$REPO_OVERRIDE" ]]; then
@@ -127,7 +129,9 @@ case "$PLATFORM" in
         [[ -n "$MILESTONE" ]] && CMD+=(--milestones "$MILESTONE")
         # Note: tea may not support assignee filter directly in all versions.
         [[ -n "$ASSIGNEE" ]] && echo "Note: Assignee filtering may require manual review for Gitea" >&2
-        "${CMD[@]}"
+        prov_rc=0
+        "${CMD[@]}" || prov_rc=$?
+        [[ "$prov_rc" -eq 0 ]] || { echo "Error: provider command failed (exit ${prov_rc}; provider failure, not a usage error)" >&2; exit 1; }
         ;;
     *)
         echo "Error: Could not detect git platform" >&2