Replace num_stages=0 with num_stages=1

[njriasan]

Summary:
num_stages=0 has been removed from TLX (and the AMD path is updated to
match), so every remaining use needs to move to num_stages=1. This diff is a
mechanical sweep of fbsource for all the places a 0 could reach a Triton
kernel.

Three mechanisms are covered:

1. triton.Config(..., num_stages=0) -- the kernel-level autotune param. This
   is the bulk of the change: the TLX idiom of passing num_stages=0 to
   suppress the compiler's auto-pipelining on top of manual TLX pipelining.
   Covers hammer/v2, hammer/v3, ads_mkl/ops/tlx,
   simplicial_attention, tritonbench fusionbench, and the TLX tutorials.

2. tl.range(..., num_stages=0) -- the loop-level tt.num_stages attribute,
   same intent, different knob.

3. Autotune sweeps that generate a 0 -- e.g. for num_stages in [0, 1, 2] in
   fbr/flash/triton, the HIP-only [0, 1] sweeps in the ragged HSTU
   attention scripts, openfold_triton, and FlagGems. The 0 is dropped
   rather than rewritten to a duplicate 1 ([0, 1, 2] -> [1, 2], not
   [1, 1, 2]).

TLX docs and agent skills that instruct readers/agents to emit num_stages=0
(RecGenHITL language profiles, kperfagent TLX prompt skills, ace
kernel_info) are updated too, so regenerated kernels do not reintroduce it.

Deliberately not touched:

• not_allowed_values = {0} guards in ads_mkl/.../hardware.py and the gem
  kernel library -- these already strip 0 from AMD sweeps and stay correct.
• TileLang kernels (tilelang.jit / T.Kernel) -- num_stages there is a
  different DSL's parameter, not Triton's.
• torch/_inductor/select_algorithm.py -- a dummy sentinel object, never
  launched.
• llama4x/mslk triton_splitk.py -- already at num_stages = 1; only a
  stale TODO comment mentions 0.
• fbcode/gem/next_gen -- an ACL'd path, so it lives in the child diff.
  Phabricator rejects diffs that touch both ACL'd and non-ACL'd paths
  (https://fburl.com/no-mixed-paths).
• third-party/triton/stable and fbcode/triton_mtia/third_party/triton
  -- reverted per request; these vendored TLX tutorial copies should be
  updated via the upstream sync instead.
• Generated snapshots under pyper_models/*/archive/ and
  minimal_viable_ai/p4p/*/cloned_files/, and unrelated num_stages concepts
  (dataswarm, shardmanager, eval pipelines).

Note: D114743914 ([Triton] [Addmm] Fix num_stages range) may overlap; expect
to prune anything already covered by other diffs.

Reviewed By: jianyuh

Differential Revision: D114751669

[meta-codesync]

@njriasan has exported this pull request. If you are a Meta employee, you can view the originating Diff in D114751669.