chore: publish 3 skills (create-2d-physics, create-tile-palette-or-rule-tiles, unity-pipeline)

[pre-shared-workflows-auth]

Skills in this PR

Skill	Files changed
create-2d-physics	4
create-tile-palette-or-rule-tiles	10
unity-pipeline	2

This PR was opened automatically. It only changes the skill folders listed above; every other skill and every root file is untouched.

Paired publish: Unity-Technologies/unity-agent-plugin#85. Each PR updates a different repo from the same source, so merge both.

[andresbayon]

Andraude: Approve. All three skills read end to end; frontmatter, links and paired publish check out. A few wording nits below for the skill authors (fix in the internal source, per CONTRIBUTING).

Tested on: Microsoft Windows 11 Enterprise 10.0.26200 (64-bit), 11th Gen Intel(R) Core(TM) i9-11900H @ 2.50GHz
Head: 2f736c4

• CI green on this head: SKILL.md frontmatter, Cycode SAST, Secrets, Vulnerable Dependencies.
• All changed files read. The .cs files, ruletile.md and hexagonalruletile.md are pure renames.
• Every relative link and anchor resolves; Tools/Generate RuleTile from Sprites matches the [MenuItem] in RuleTileGenerator.cs.
• Docs URLs checked: version-appropriate pages return 200; the component pages exist from 6000.7, matching the skill's 6000.7 requirement.
• No secrets, internal URLs or personal paths.
• Paired publish unity-agent-plugin#85: unity-pipeline SKILL.md and SECURITY.md are byte-identical to this PR.

Non-blocking:

1. create-2d-physics/SKILL.md:69: "the three routes above", but the routes are defined in the Key below.
2. create-2d-physics/SKILL.md:49: "Volume" looks like a leftover from a render-pipeline skill; "The compiler reads using UnityEngine" is unclear.
3. create-2d-physics/SKILL.md:80: the probe uses eval --code '...', while unity-pipeline documents eval "<code>" positionally. Worth aligning on one form.
4. create-tile-palette-or-rule-tiles/references/ruletile-createfromsegment.md:120: "in the scripts/ folder" should be ../scripts/; lines 203-204 assume sprite-segment-3x3grid ships alongside, which won't hold when only this skill is installed.
5. ruletile-createempty.md lines 3 and 10: "This skill is only for empty RuleTiles" reads as a leftover from before the split into references.