docs: strip grill changelogs + cast refs from docs/plans (#Phase2 WI-3)

[primetimetank21]

WI-3: Strip grill changelogs + cast-name refs from docs/plans/

Implements WI-3 of the approved Phase 2 docs-alignment plan
(/.squad/repos/dev-setup/plans/phase2-docs-alignment.md, Section 4 WI-3, Sections 2 D3/D4).

---

Per-doc summary of changes

441-profile-path.md

• Deleted: 4 grill changelog blocks at top of file (## v5 Changes, ## v5.2 Changes, ## v5.1 Changes, ## v4 Changes) including all reviewer-finding tables with Pluto/Chip/Doc labels. These sat between the YAML front-matter and the first spec section (## 1. Problem).
• Scrubbed: Cast-name attribution *(updated v4 -- Doc/Chip)* from body heading v3-D4; substantive content of that decision preserved verbatim.

451-pwsh-parity-gaps.md

• Deleted: Entire ## Revision History section (end of file); front-matter updated field + git log provide sufficient history.
• Scrubbed (6 body locations):
  • ## CI Integration heading: removed (v2 addition -- resolves Mickey BLOCKING-1/BLOCKING-2, Goofy Finding-1)
  • T7 detail heading: removed (v2 -- replaces vague "assert shebang valid", resolves Mickey MAJOR-2)
  • Risk Assessment: removed trailing (v2 decision -- resolves Mickey MAJOR-1 / Goofy T_C/T_D note) from one sentence
  • Risk Assessment: Use established ASCII safety pattern from chip/history.md -> Use the established ASCII safety pattern (dead squad artifact path removed)
  • Open Questions: RESOLVED (by Goofy). -> RESOLVED.
  • Out-of-Scope heading: removed (v3 addition -- resolves Goofy Round 2 caveat)

468-customizable-install.md

• Deleted: All 10 grill changelog blocks (## v5 Changelog through ## v14 Changelog, ~170 lines).
• Scrubbed (3 body locations):
  • Real-Defaults Drift Test heading: removed (v5 fix #3 -- Duck-2)
  • Blocker Resolution Map: Donald-1 (baseline format mismatch) -> baseline format mismatch
  • Blocker Resolution Map: Duck-2 (real defaults drift unprotected) -> real defaults drift unprotected
• Added: One-line NOTE banner near squad-cli sections: > NOTE: squad-cli entries below are stale pending #468 implementation. (per plan recommendation R5/WI-3 notes)

---

squad-cli content: deliberately preserved (deferred to #468 implementation)

Per Phase 2 D4, squad-cli feature content in 468 is left entirely untouched:

• DEFAULT_TOOLS bash array (Linux)
• $DefaultTools PS array (Windows)
• $ToolRegistry entry ('squad-cli' = { Install-SquadCli })
• Fixture Provenance (Linux + Windows fixture order lists)
• Graceful Degradation table + npm-absent examples

The pre-WI-3 file had 21 squad-cli/Install-SquadCli references total. Of these, 10 were in the changelog blocks (correctly deleted with the changelogs, as noted in the authoritative plan appendix: "v10/v11/v12 changelogs: squad-cli.sh/squad-cli.ps1 refs -- DELETED by WI-3"). The remaining 11 body references are all preserved. The NOTE banner adds one additional reference (meta-comment only). Total post-scrub: 12 matching lines.

---

Verification

• git grep -niE "mickey|goofy|jiminy|pluto|donald|grill" -- docs/plans/: ZERO matches
• git grep -niE "\bduck\b|\bchip\b|\bdale\b|\bdoc\b" -- docs/plans/: 4 hits, all ordinary English:
  • 451:90: inline doc comment -- doc = code comment (ordinary)
  • README.md:11: Every plan doc -- doc = document (ordinary)
  • README.md:35: doc kept for reference -- doc = document (ordinary)
  • README.md:36: plan doc (note supersedes) -- doc = document (ordinary)
• ASCII-clean: zero bytes > 0x7F in all 3 files post-scrub
• Only changelog/cast content removed; no substantive spec content deleted
• 3 files changed, 12 insertions(+), 244 deletions(-)