fix: batch of small robustness/correctness fixes from @kyssta-exe

Salvages 8 distinct fixes from a batch of PRs by @kyssta-exe, reapplied
onto current main (original branches were stale) with a few refinements.

- cron(jobs.py): load_jobs() validates top-level JSON shape — a bare
  list auto-repairs into the {"jobs": [...]} dict; scalars/null raise a
  clear RuntimeError instead of an uncaught AttributeError that took
  down the whole cron subsystem (#37065, closes #36867).
- web(web_server.py): close the per-action log file handle after Popen
  so the parent stops leaking one fd per spawned action (#36843).
- web(web_server.py): DELETE /api/env returns 400 for invalid key names
  instead of a misleading 500, mirroring PUT /api/env (#36840).
- gateway(gateway.py): read /proc/<pid>/cmdline inside a with-block so
  the fd is released immediately instead of relying on GC (#36804).
- web-tools(web_tools.py): include "xai" in check_web_api_key() so a
  configured X.AI web backend reports as available (#36802).
- compression(conversation_compression.py): mark the feasibility check
  done only after it completes, and default the gate to "not checked"
  if the attribute is missing (#36803).
- completion(completion.py): replace `ls` with directory globbing in the
  generated bash/zsh/fish profile listers — handles names with spaces
  and skips non-directory entries (#36806).
- terminal-tool(terminal_tool.py): drop a duplicate `import threading`
  (#36808).
- claw(claw.py): the migrate recommendation now points at the real
  `hermes gateway stop` command instead of the non-existent
  `hermes stop` (#36795, #36796, closes #36771).
- tests: guard against a leaked HERMES_CRON_SESSION breaking gateway
  approval tests — add it to the hermetic conftest unset list (root
  cause, protects every test) and pop it in the affected test's
  setup_method (#36796).

Co-authored-by: kyssta-exe <kyssta-exe@users.noreply.github.com>

hermes_cli/completion.py

@@ -105,7 +105,9 @@ _hermes_profiles() {{
     local profiles_dir="$HOME/.hermes/profiles"
     local profiles="default"
     if [ -d "$profiles_dir" ]; then
-        profiles="$profiles $(ls "$profiles_dir" 2>/dev/null)"
+        for f in "$profiles_dir"/*/; do
+            [ -d "$f" ] && profiles="$profiles $(basename "$f")"
+        done
     fi
     echo "$profiles"
 }}
@@ -206,7 +208,7 @@ _hermes_profiles() {{
     local -a profiles
     profiles=(default)
     if [[ -d "$HOME/.hermes/profiles" ]]; then
-        profiles+=("${{(@f)$(ls $HOME/.hermes/profiles 2>/dev/null)}}")
+        profiles+=($HOME/.hermes/profiles/*(N/:t))
     fi
     _describe 'profile' profiles
 }}
@@ -260,7 +262,9 @@ def generate_fish(parser: argparse.ArgumentParser) -> str:
         "function __hermes_profiles",
         "    echo default",
         "    if test -d $HOME/.hermes/profiles",
-        "        ls $HOME/.hermes/profiles 2>/dev/null",
+        "        for d in $HOME/.hermes/profiles/*/",
+        "            basename $d",
+        "        end",
         "    end",
         "end",
         "",