* Draft changelog for v0.17.2

Consolidates the Unreleased section (which already included the real
entries added by #526/#532 on merge) with entries for the remaining
PRs merged since v0.17.1 (#487-#535), and retitles it as 0.17.2.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Bump version to v0.17.2

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Fix confirmed small bugs from the pre-release audit

- isunitspace: require dim(V) == 1 for GenericUnit sectors (#537)
- GradedSpace ⊕/supremum: check unit homogeneity of the result (#538)
- isconj(::ComplexSpace): return isdual(V) instead of always true (#539)
- multi_associator: return a vector, not a scalar, on early-exit for
  GenericFusion (#540)
- split(f, 0): use leftunit(f.coupled) instead of indexing an empty
  uncoupled tuple (#541)
- repartition: return a Pair in the identity branch, matching every
  other branch (#542)
- Mooncake scalar_pullback: accumulate into the tangent instead of
  overwriting it (#543)
- rand/randn/randexp/randisometry(rng, T, space): fix one(domain) typo (#544)
- pinv(::DiagonalTensorMap): fix inverted atol/rtol defaulting and
  empty-tensor throw (#545)
- t1 / t2: promote to a float scalartype, matching t1 \ t2 (#546)

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Add changelog entry for the audit bugfixes

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Address fable review findings on the audit bugfixes

- split(f, 0): also guard innerlines_extended construction, which
  still indexed the empty uncoupled tuple for a 0-leg tree
- pinv(::DiagonalTensorMap): use eps (not sqrt(eps)) for the default
  rtol, matching _default_rtol's convention and dense LinearAlgebra.pinv

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Address tuicr review comments on the audit bugfixes

- pinv(::DiagonalTensorMap): reuse _default_rtol instead of
  duplicating its formula
- Add regression tests for split(f, 0) on a genuine 0-leg tree and
  for multi_associator's early-exit branch on a GenericFusion sector

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* fix planar issues after MPSKit test rerun

* harden Mooncake scalar pullback

---------

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>