Problem:

- annotation-usage-error and code-style-check are disabled.
- vim.inspect relies on a dummy self-assignment for docgen, and its help
  omits parameter and option details.
- LuaLS fallback types obscure iterator inference.
- Docgen hardcodes public function names and appends separately sorted
  files, leaving shared helpers under the inspector heading.

Solution:

- Enable annotation-usage-error and code-style-check, and fix misplaced
  annotations.
- Document vim.inspect's callable module directly, removing the dummy
  assignment. Describe its parameters, option defaults and process
  callback.
- Remove LuaLS iterator fallbacks, correct iterator signatures and check
  values that the improved inference identifies as optional.
- Parse callable modules, require bindings and parent module references.
  Derive public names and inherited function docs from these links,
  including missing help for vim.async.semaphore() and vim.version().
- Export vim.lsp.tagfunc directly with lazy loading and document its
  implementation instead of maintaining a wrapper.
- Group files in section_order, replacing append_only and merge_files.
  Merge declarations before sorting each section, placing shared helpers
  in the main vim section and keeping vim.inspect in alphabetical order.
- Add basic parser coverage for callable modules and module links.

AI-assisted

Problem: Argument type mismatches are excluded from EmmyLua checks.

Solution: Correct runtime annotations and calls, document local checker
workarounds, and enable the diagnostic.

AI-assisted

Problem:
POSIX-compatible Ex-mode requires special-cases all over the codebase to
match various quirks that don't actually matter to users.
- The main utility of *interactive* Ex-mode is its REPL behavior, and
  that can be achieved with `cmdwin`, which also gains extra UX
  benefits.
- The main utility of *non-interactive* `nvim -es` is for shell
  scripting, where Ex-mode quirks are mostly unhelpful (e.g. the
  "Entering Ex mode" message).

Solution:
- Reimplement *interactive* Ex-mode as a "persistent, insert-mode
  cmdwin" in Lua.
  - "nvim -e/-E" is simply an alias to "gQ".
- Reframe *non-interactive* Ex-mode (`nvim -es`) as "script mode".
  - Drop POSIX Ex-mode quirks.

Improvements:
- "nvim -V1 -es" output ends with a final newline!
- "nvim -V1 -es" no longer shows the "Entering Ex mode" msg. (This was
  pointless noise, unwanted for scripting purposes.)
- stdin is no longer typeahead. Scripts (":lua io.read()") can read
  stdin as data.
- Empty line is a no-op: a stray blank line no longer moves the cursor
  (deviates from POSIX ex "+1"), no longer exits 1 at EOF (E501).

Preserved behavior:
- cursor starts at "$"
- mode()=="cv" (for non-interactive)
- multiline commands (:append/:function/heredoc pull continuation lines)
- bare-range print
- :print=>stdout
- -V1=>stderr
- CRLF input
- continue-after-error and exit codes

Dropped (regressed) POSIX behavior (non-interactive):
- Event loop only ticks while/between commands, not while blocked
  waiting for a stdin line.
- ":g/pat/visual...Q"
- input()/getchar()/":s/x/y/c" no longer consume stdin lines as
  answers: Nvim stops at end-of-input, skipping the rest of the script,
  exit 0. Use ":lua io.read()" instead.
  - If users care about this they should use interactive Ex-mode (`gQ`).
- ":@r" stops at end of the register instead of continuing to read
  cmdline input from stdin.

Problem:
`nvim__ui_detach` was added in 85e0559d46c7 in order to implement
`detach_others` from Lua. Using Lua in this case is doing more harm than
good.

Solution:
Extract `ui_detach_channel`, which also allows it to be used for the
"self detach" path from `ex_detach`.

Bonus: the old MSWIN path always called `os_swap_to_hidden_console()`;
now `ui_detach_channel` only does so for a stdio channel. For the common
stdio TUI this is identical; for a socket UI it's more correct (no
parent console to swap).

Problem:
Not easy for one UI to kick the others off a shared Nvim server.

Solution:
Treat `:%detach` as detach-other-UIs.

Problem:
`:restart` does not preserve window layout, etc.

Solution:
- Change `:restart` to save/restore a session automatically.
- Introduce "bang" variant `:restart!` to restart *without* session
  save/restore.
- Introduce `v:startreason`.
- `ZR` maps to `:restart!`.

Problem:
When showing the :connect menu, it is useful to know which servers
are most-recently active. But we don't have a good way to detect that.

Solution:
- Introduce `v:useractive`.
- Include this timestamp in `serverlist({info=true})`.

Co-authored-by: Justin M. Keyes <justinkz@gmail.com>
Signed-off-by: Szymon Wilczek <swilczek.lx@gmail.com>