`simp at *` does not target all hypotheses

Prerequisites

Please put an X between the brackets as you perform the following steps:

• Check that your issue is not already filed:
  https://github.com/leanprover/lean4/issues
• Reduce the issue to a minimal, self-contained, reproducible test case.
  Avoid dependencies to Mathlib or Batteries.
• Test your test case against the latest nightly release, for example on
  https://live.lean-lang.org/#project=lean-nightly
  (You can also use the settings there to switch to “Lean nightly”)

Description

simp/dsimp at * is documented as targeting all hypotheses and the goal, but it does not do so.

Steps to Reproduce

example (i : Fin (n + 0)) : Fin n :=
  by dsimp at *; assumption

Expected behavior: dsimp at * simplifies i : Fin (n + 0) to i : Fin n

Actual behavior: dsimp made no progress. Replacing * with the list n i ⊢ (or just i) succeeds. simp also shows the same behavior

Versions

Lean 4.21.0-nightly-2025-06-09

Impact

Add 👍 to issues you consider important. If others are impacted by this issue, please ask them to add 👍 to it.

Start by running the minimal reproducer against the reported Lean nightly version and compare dsimp at * with the explicit target list n i ⊢; the issue states that both dsimp and simp show the problem. Trace the implementation of hypothesis-and-goal target expansion, and consider the issue done when the reproducer simplifies i : Fin (n + 0) to i : Fin n using at *.