The CLI was hardcoding `llama_parallel_slots=4` in `run_kwargs` at
`unsloth_cli/commands/studio.py`, leaving users unable to tune the
concurrent decode slot count even though the engine, KV-cache math,
and `studio.backend.run.run_server(llama_parallel_slots=...)`
plumbing all already accepted any N. This change adds a `--parallel`
/ `--n-parallel` / `-np` typer option (default 4 -- matches the
previous hardcoded value), forwards it into `run_kwargs`, and pins
the new surface with 4 unit tests.

Per-request state in `routes/inference.py` is already isolated
(`cancel_event` and `prev_text` are per-request locals in every
streaming handler; the `_lock` / `_serial_load_lock` only wrap
load/unload, not chat completions), so no concurrency refactor is
needed alongside this -- the engine layer already handles N
concurrent requests on one loaded model when llama-server is told
to.

Range guards: 1 <= N <= 64. With higher N each slot gets ctx/N KV
cache; users tuning this should be aware that per-call context
shrinks proportionally.

`unsloth studio` (the bare default command, no subcommand) still
defaults to llama_parallel_slots=1 via `run_server`'s own default;
this PR does not change that path -- it only exposes the knob on the
one-liner `studio run` command that already silently used 4.

`unsloth studio run` re-execs into the Studio venv when invoked from
outside it (the common path). The arg-builder forwards every typer
option but the new --parallel, so the child re-execs at the default 4
and any user value is silently dropped. Worse: pre-PR users who
already pass `-np N` as a pass-through extra (where llama.cpp's
last-wins parsing made it stick) silently lose N after this PR lands.
Forward --parallel explicitly in the re-exec arg list.

While auditing the re-exec path, also drop the colliding 1-char
short aliases -m (--model) and -f (--frontend) plus the redundant
-hfr. Click's short-option clustering had been silently mis-parsing
~11 llama-server short flags via the pass-through path: -fa as
`-f a`, -mg 0 as `-m g` + stray 0, -fitt 1024 as `-f itt` + stray
1024, -hff path as `-f f` + stray `-h path`, -cmoe / -cram / -sm /
-ncmoe etc. The docstring promise ("any flag this command does not
recognize is forwarded verbatim") was silently violated.

-hf (2-char) is kept because Click treats multi-char shorts atomically
(no clustering of -hff / -hfv / -hffv / -hft) and -hf is documented
in basics/api/README.md. --model / --hf-repo / --frontend long forms
all unchanged. studio_default keeps -f because it has no pass-through.

Tests:
- test_studio_run_parallel_flag.py: 8 new re-exec coverage cases
  (all 3 aliases, 3 platforms via sys.platform mock, pre-PR `-np`
  regression, mixed with pass-through extras).
- test_studio_run_short_alias_clashes.py (new): surface checks that
  the removed shorts cannot reappear, plus 11 parametrized cases
  proving each previously-broken llama-server short flag now passes
  through verbatim, plus a happy-path test that documented -hf still
  works for `org/repo:variant` syntax.

All 27 tests pass. Negative test (revert either fix) shows the new
tests catch the regression.

…5741 comments (#5746)

* ci: broaden Linux llama.cpp runtime pattern to lib*.so*

#5741 patched the explicit Linux pattern list to add
``libllama-*-impl.so*`` after ggml-org/llama.cpp#23462 (between
b9279 and b9283) split each binary's entry code into a paired
``lib<binary>-impl.so`` shared library. Same class of upstream
repackaging will hit us again whenever a new shared lib is added.

Mirror what macOS already does and replace the per-lib list with a
single ``lib*.so*`` glob. ``copy_globs`` (line 3614) unions
patterns, so the per-variant ``libggml-cuda.so*`` / ``libggml-hip.so*``
entries were never filtering anything; the spec lives in
``runtime_payload_health_groups`` (line 5209) which keeps the
explicit minimum-required list per variant.

Dry-run against b9296-bin-ubuntu-x64.tar.gz: 40 files copied (all
ggml, llama, mtmd, impl variants + the two binaries we ship), 22
skipped (other CLIs, rpc-server, LICENSE). Functionally equal to
the post-#5741 set.

* cleanup: trim #5741 comments on the pydantic split

Comments added in #5741 explained the original bug in full each
time. They are mostly redundant with the commit message and the PR.
Trim them to one short paragraph per site.

No behavior change.

* ci: narrow Windows runtime pattern to llama-server.exe + llama-quantize.exe

Studio only invokes llama-server and llama-quantize. Mac and Linux
already filter to those two binaries; Windows was the odd one out
with ``*.exe`` copying every CLI upstream ships (llama-cli,
llama-bench, llama-mtmd-cli, ...).

Dry-run on b9296 (win cpu-x64, cpu-arm64, cuda-13.1, hip-radeon):
20 unused EXEs skipped per variant, all DLLs (incl. the new
llama-*-impl.dll family) still copied via ``*.dll``.

``existing_install_matches_choice`` already checks llama-server.exe
exists explicitly (line 5297), so the health gate is unchanged.

for more information, see https://pre-commit.ci

…nd missing model

Three additional edge cases for the -m / -hfr / -f preprocessor:
- `-m unsloth/foo:UD-Q4_K_XL` round-trips through both the preprocessor
  and _split_repo_variant so the child sees --model + --gguf-variant.
- `-m=foo` inline value form is promoted just like `-m foo`.
- Missing --model after the preprocessor raises typer.Exit(2) cleanly
  (replacing typer's pre-PR required-flag enforcement now that --model
  is Optional to allow the legacy promotion path).

for more information, see https://pre-commit.ci

…-in-depth

Three Opus subagent reviewers (adversarial-user / maintenance /
cross-file consistency) flagged a consistent set of cleanups; folded
into one commit to avoid the pre-commit.ci force-push race.

unsloth_cli/commands/studio.py:
- Extract _PARALLEL_MIN / _PARALLEL_MAX / _PARALLEL_DEFAULT_RUN /
  _PARALLEL_DEFAULT_PLAIN module-level constants and use them in both
  typer Options (plain studio_default = 1, studio run = 4).
- _expand_attached_np_short now rewrites -np<junk> when the suffix
  starts with a digit (or signed digit) so '-np8x' surfaces as a
  clean '-np takes an int' typer error instead of a baffling
  '--port invalid' complaint after Click clusters '-n -p 8x'.
- Re-exec forwarding emits --load-in-4bit / --no-load-in-4bit
  explicitly in both directions; previously the True default relied
  on both layers sharing the same default forever.
- run() docstring now explicitly says --parallel / -np pass-through
  via llama_extra_args is denied (use the typer flag above).

studio/backend/run.py:
- Mirror the parallel constants and route the argparse default,
  range check, and error message through them. Help text mentions
  the asymmetry with 'unsloth studio run' so direct-launch dev users
  aren't confused by Default 1 in isolation.

studio/backend/core/inference/llama_server_args.py:
- _flag_name strips surrounding whitespace before denylist lookup so
  a caller can't slip a managed flag past the boundary with a
  trailing space (the trimmed form is what downstream parsers see).

Tests:
- New typer-aliases-subset-of-denylist invariant: every alias the
  typer Option claims as --parallel on run() MUST be in the backend
  parallel denylist group. Catches the failure mode where someone
  adds a new alias and forgets the boundary.
- Extended denylist parametrize to cover ~14 previously untested
  aliases (-mu, -dr, -hfv/-hfrv/-hffv family, -mmu, full --ui group,
  --models-preset / --models-autoload / --no-models-autoload).
- Whitespace-padded denylist rejection (' --parallel', '-np ', etc).
- --load-in-4bit re-exec test pinning both polarities + default.
- -np<junk> argv rewriter regression tests.
- Cross-reference headers between the two test files.

Comment-only pass over the seven PR-touched files; trim verbose
docstrings, collapse multi-line section dividers, and drop
redundant prose that the code already conveys. No behaviour change.

Resolve studio.py conflict by keeping both:
- PR #5737's `_PARALLEL_*` constants block
- main's `_iter_editable_studio_source_roots` + `_find_frontend_dist`
  helpers (PR #5782).

run.py auto-merged cleanly. 215 PR tests still pass.

`--embedding` and `--rerank` flip llama-server into single-endpoint
mode, which breaks Studio's /v1/chat/completions hop. llama-server's
own `--tools` flag silently stacks on top of Studio's tool policy
resolved by `--enable-tools` / `--disable-tools`.

Add all three (plus the `--embeddings` / `--reranking` plural aliases)
to the boundary denylist so HTTP /load and pass-through extras both
reject them cleanly instead of silently desyncing the server surface.

Test added to the existing `test_denylist_rejects_all_aliases`
parametrize. 220 tests pass.

Two cross-OS CI findings:

1. `test_typer_parallel_aliases_are_subset_of_backend_denylist` was
   doing `from core.inference.llama_server_args import _DENYLIST_GROUPS`
   which triggers `core/inference/__init__.py` and pulls in the full
   backend chain (fastapi / structlog / loggers / utils.hardware).
   The invariant only needs the constants tuple, so load the module
   directly via `importlib.util.spec_from_file_location` -- the test
   now runs with just typer + pytest installed.

2. `test_legacy_frontend_alias_still_promotes_to_frontend` asserted
   the literal string `"/tmp/dist"` after the value round-trips through
   `Path()`. On Windows `str(Path("/tmp/dist"))` is `"\tmp\dist"`, so
   the assertion tripped on the same logical path. Compare via
   `Path(x) == Path("/tmp/dist")` so the test passes on every OS.

Both surfaced by the staging-4 cross-OS CI; no production-code change.
220 tests still pass locally.

for more information, see https://pre-commit.ci

Same fix as the previous CLI-test commit: import the module via
`importlib.util.spec_from_file_location` instead of
`from core.inference.llama_server_args import ...`, so the test no
longer needs the full backend chain (fastapi / structlog / loggers /
utils.hardware) installed via `core/inference/__init__.py`.

The boundary validator is intentionally dependency-free; its unit
tests should reflect that.

PR #5784 ("Improve image generation UI") rewrote the message-input
textarea's static `aria-label="Message input"` into a JSX conditional
`aria-label={overlay ? "Image edit instructions" : "Message input"}`
but did not update the RTL bidi-attribute regression test, leaving
the literal-string `find('aria-label="Message input"')` anchor with
no match. The `Repo tests (CPU)` job has been red on main since.

Anchor on the inner `"Message input"` string literal instead -- it
survives both spellings and still pins the same textarea element so
the `dir="auto"` assertion has the right block to inspect.

Verified by re-running the exact CI command:
  954 passed, 3 skipped, 23 deselected (was 948 passed, 1 failed).