validate-repository-naming.py: the --link-source <link>=<path> the gate offers for a chain link holding = is read as a bare PATH when typed, so it never verifies that link #980

Found during #949's fix round 1, as NIT-2 of RV949 (lane 4's review of #949). It predates #949.

Goal

For a declared-unverified chain link whose name holds =, the naming gate offers only sources that verify that link's tree when typed as printed.

State

At main 66177b62 and at #949's head ced3d7c2. RV949 measured the same at the base 64464d31 and the head 8c5d6051.

What happens

• LinkSources.__init__ in scripts/validate-repository-naming.py takes a --link-source key as the text before the value's first = (typed.partition("=")).
• With the chain openXdox,open=y,openInk, --link-source open=y=<tree> gives the key open. No chain names open, so the whole value is read as a bare PATH for the first link.
• open=y stays declared-unverified, and its WARNING offers exactly that --link-source open=y=<path>.

Evidence

Run from an empty folder at ced3d7c2, where <tree> declares openInk:

validate-repository-naming.py --pins openXdox --referent-chain openXdox,open=y,openInk --link-source open=y=<tree> codexInk
WARNING link-source-unreadable: open=y=<tree> (--link-source) could not answer for openXdox: no such file or directory
It was read as a PATH: `open` is not a link of a referent chain here (links: openXdox, open=y, openInk).
declared-unverified: open=y declaring a pin on openInk ... (a sibling checkout, SHAPE_PIN_SOURCE_OPEN_Y, or --link-source open=y=<path> would let it be read)

The run exits 0.

• With SHAPE_PIN_SOURCE_OPEN_Y=<tree> instead, the WARNING for open=y is gone. Only the --link-source offer fails to cure.
• setup-project.py's step (5) refuses such a link as chain-link-malformed.

Direction

One of:

• (a) Read a --link-source key the way --link-remedy reads its link since setup-project.py and validate-repository-naming.py: step (4) reads and names what step (5) does, --link-remedy reads a link holding =, strips its words and notes an unused one, and the Windows hand clone passes -c core.autocrlf=false (#907, #926) #949: the longest text before an = that names a chain link and leaves a path after it. Keep the ./PATH rule, and the documented rule for a directory spelled like the whole value.
• (b) For a link holding =, _chain_link_findings offers only the sources that cure it: the variable and a sibling checkout.

The gate is a pinned copy, so either one adds an upgrade row.

Verify

• A row with the chain openXdox,open=y,openInk in which one of these holds:
  • typing the printed offer verifies open=y, with no declared-unverified line for it and no link-source-unreadable;
  • no such offer is printed.
• The docs guards, and tests/test_cli_reference.py if the help text changes.

Lane: openreposhape-3 (openRepoShape-3)