#5732: preserve compact | pipe when target formation floats away

[yegor256]

Closes #5732.

Problem

After #5684 the printer emits the | pipe-application form, but the adjacency guard at to-eo-tree.xsl:223 only fires when the pipe target is the immediately-preceding sibling. When a pipe target formation floats up to become a formation attribute (#5526) while its pipe application stays nested inside another expression (the "floated away" case), the guard fails and the line prints as an ordinary application — destroying the compact | args author spelling on the first eo:format. This is exactly the recursive-helper case in eo-runtime/src/main/eo/tuple/front.eo.

merge-monikers.xsl already un-hoists ordinary > name bindings back onto their use-site, but it deliberately skips pipe-floated bindings (not(exists($attr/@pipe))) and references carrying arguments (not($ref/o)) — which is precisely what a | args use is.

Fix

Add renest-pipe-monikers.xsl, a small targeted pass mirroring merge-monikers.xsl, registered right after it in the Xmir train (before to-eo-tree.xsl). For a formation attribute whose only reference is a single @pipe application that no longer sits directly after it, the pass copies the formation back in front of that pipe use-site and drops the floated original. The pipe then reads its predecessor from the immediately preceding sibling, so the existing adjacency guard fires and the | head is emitted. Both spellings parse to identical XMIR, so re-nesting is safe.

It is gated on the formation having exactly one reference which must be the pipe use — the same single-host condition merge-monikers uses (#5706) to keep the round trip converging. A second reference would fall out of scope once the formation moved into the pipe's argument block. A formation already adjacent to its pipe use is left untouched.

Changes

• renest-pipe-monikers.xsl — the new pass.
• Xmir.java — register the pass in the transformation train after merge-monikers.
• to-eo-tree.xsl — update the pipe-application comment to note the floated case is now re-nested upstream.
• pipe-floated-recursive-helper.yaml — new print-pack modeling the tuple/front.eo recursive helper; the | now survives the round trip.
• pipe-in-argument-block.yaml — updated expected output: the pipe is now preserved instead of degrading to a bare application.

Testing

XmirTest (all 139 parameterized print-pack / eo-pack cases) passes, including the round-trip check that printed EO reprints to the very same EO.

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Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
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0.0% Coverage on New Code
0.0% Duplication on New Code

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