chore(varve): bump to layer 2026.09.1, and correct two things the bump exposed

[avrabe]

Layer 2026.09.1, pinned by digest (sha256:893dbbf4…bd498) — a name-only pin stops
resolving when rolling republishes under a second manifest digest (varve#115).

synth 0.60.0 -> 0.61.0     meld 0.52.0 -> 0.53.0
spar 0.40.0                loom 1.4.1     rivet 0.35.0     witness 0.43.0

All gates re-run under it: cross-arch PASS (ARM 13/13 seams held), driver-components
PASS, graph-env PASS, object-freshness PASS, rivet validate PASS.

1. The RISC-V ledger's reason was stale

It said "rv32 emits a dangling synth_func_N for a declined internal, exit 0".
synth 0.61.0 fixed exactly that (#1104). Measured under the new layer:

exit=1
Error: #1102: 5 retained function(s) relocate against function(s) this compile DECLINED
… refusing to emit it rather than shipping an unlinkable object with exit 0

The 13 drivers still don't cross, so the ledger's contents are right and the gate
stays green — but its stated justification described a defect that no longer happens. A
ledger that is accurate about what fails and wrong about why is the kind nobody
re-reads. Corrected to describe the pinned toolchain's actual behaviour.

2. The CI synth pin drifted, again

drv-cross-arch.yml downloads its own synth rather than resolving through varve, so the
pin exists twice. Its own comment reads:

KEEP IN SYNC WITH varve.toml … the pin exists twice and can drift. It just did.

And it just did again — varve.toml resolved 0.61.0 while the workflow still said 0.60.0.

Worth naming rather than just fixing: that warning comment was written by the previous
drift, and did not prevent the next one. A note is not a control. These two pins want a
gate that compares them, which I have not built here.

3. What 2026.09.1 does not do

It does not carry synth's region-table symbols (__synth_mem_base_N / _size_N),
which merged after v0.61.0. Verified rather than assumed — the same two-tenant module
under the pinned 0.61.0:

pinned 0.61.0   compile exit=0, ZERO synth_mem symbols
synth main      4 symbols

So the v0.5.0 two-tenant demonstrator stays an unpinned prototype. It cannot become
committed evidence until a released synth carrying those symbols lands in a layer.

Kill-criterion: varve.toml and drv-cross-arch.yml name different synth versions.

🤖 Generated with Claude Code

https://claude.ai/code/session_011QG86sovTbfnPNY9SfhSmo

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