* fix: harden `hermes update` against diverged history, non-main branches, and gateway edge cases
The self-update command (`hermes update` / gateway `/update`) could fail
or silently corrupt state in several scenarios:
1. **Diverged history** — `git pull --ff-only` aborts with a cryptic
subprocess error when upstream has force-pushed or rebased. Now falls
back to `git reset --hard origin/main` since local changes are already
stashed.
2. **User on a feature branch / detached HEAD** — the old code would
either clobber the feature branch HEAD to point at origin/main, or
silently pull against a non-existent remote branch. Now auto-checkouts
main before pulling, with a clear warning.
3. **Fetch failures** — network or auth errors produced raw subprocess
tracebacks. Now shows user-friendly messages ("Network error",
"Authentication failed") with actionable hints.
4. **reset --hard failure** — if the fallback reset itself fails (disk
full, permissions), the old code would still attempt stash restore on
a broken working tree. Now skips restore and tells the user their
changes are safe in stash.
5. **Gateway /update stash conflicts** — non-interactive mode (Telegram
`/update`) called sys.exit(1) when stash restore had conflicts, making
the entire update report as failed even though the code update itself
succeeded. Now treats stash conflicts as non-fatal in non-interactive
mode (returns False instead of exiting).
* fix: restore stash and branch on 'already up to date' early return
The PR moved stash creation before the commit-count check (needed for
the branch-switching feature), but the 'already up to date' early return
didn't restore the stash or switch back to the original branch — leaving
the user stranded on main with changes trapped in a stash.
Now the early-return path restores the stash and checks out the original
branch when applicable.
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Co-authored-by: kshitijk4poor <82637225+kshitijk4poor@users.noreply.github.com>