Generic command palette: AGENTS.md, scoped review, sessions, model override

[anirudhakulkarni]

Summary

• ByteAskReview now prompts for scope (uncommitted / base branch / commit / whole repo) instead of always reviewing everything, matching what byteask review actually supports.
• ByteAskAgents opens or scaffolds the nearest AGENTS.md — the primary lever for steering the agent, previously unreachable from the plugin.
• ByteAskSessions surfaces archive/unarchive/delete alongside a "browse all sessions" entry (existing resume/fork unchanged).
• ByteAskModel sets a transient -m/-c override for future invocations without editing Lua config; ! clears it.
• CI load-test and AGENTS.md docs updated to the resulting 11-command set.

All new/changed commands stay in the plugin's existing zero-dependency style (vim.ui.select/vim.ui.input, jobstart/termopen), no new plugin dependencies, no engine changes.

Test plan

• stylua --check . — clean
• luacheck lua/ plugin/ --globals vim — 0 warnings/errors
• actionlint .github/workflows/*.yml — clean
• Headless load-test asserting all 11 :ByteAsk* commands register
• Unit-level checks of new logic (headless nvim, no real byteask binary needed):
  • apply_common_flags layers ByteAskModel overrides over setup() defaults and falls back cleanly on clear
  • find_upward locates AGENTS.md walking up the tree, returns nil at root when absent
  • ByteAskReview scope selection builds the exact --uncommitted/--base <branch>/--commit <sha> argv matching byteask review --help
• Manual exercise against a live byteask install (needs a maintainer with the CLI + a real session to fully exercise ByteAskSessions archive/delete against a live account)

🤖 Generated with Claude Code

[anirudhakulkarni]

Ran a self-review pass (line-by-line, removed-behavior, cross-file, reuse/simplification/efficiency, altitude, CLAUDE.md-conventions angles) before merging. Found and fixed one real bug: config.set_override used vim.tbl_deep_extend('force', ...) to merge the new override into the old one, so blanking the model or -c field in a second :ByteAskModel call silently kept the stale value instead of clearing it — contradicting the prompt's own "blank = default"/"blank = none" text. Fixed in 75b90d9: set_override now replaces wholesale, the model commits as soon as the first prompt resolves (so cancelling the second prompt can't discard it), the -c prompt prefills with the current overrides, and malformed -c entries now warn instead of vanishing silently. Also improved session archive/unarchive/delete failure messages to include stderr. Re-verified all argv-construction paths headlessly after the fix; CI green.