[stack 17/20] spec(gazprea): reconcile procedure call-site restatement

[Sir-NoChill]

Origin: spec-patches/07-fix-procedure-call-sites.patch (backlog audit). Applied via 3-way merge (context drift only; substantive change unchanged).

What

gazprea/spec/procedures.rst — the chapter states procedure call sites in two places: an authoritative bullet list at the top, and a prose restatement further down. The restatement (a) dropped declaration-RHS and call statements from the site list, and (b) omitted casts from the operator whitelist. Whichever passage a reader hit first won.

Restatement now explicitly defers to the bullet list ("As listed at the top of this chapter, procedure calls may appear only on the RHS of a declaration, on the RHS of an assignment, or in a call statement"), and adds casts to the operator whitelist.

Audit — ambiguities for reviewer attention

• Casts as an operator: the fix adds "and casts" to the previously "unary operators" whitelist. Confirm casts are actually legal on a procedure-call result; if not, they should be dropped in the other direction (leaving the restatement narrower than the bullet list).
• Control-expression ban: the restatement calls out control-flow control expressions specifically. If the bullet list at the top of the chapter enumerates disallowed sites (rather than allowed ones), the restatement should match its inverse — cross-check the top of the chapter to confirm consistency.

Stack

Depends on #127; part of stack #121.

🤖 Backlog patch applied by Claude Code

[Sir-NoChill]

Collapsed into #139 — a single consolidated PR of the whole stack (all 40 commits preserved). The flagged questions from this PR are aggregated in #139's description; this branch and thread remain here for reference. Closing in favour of #139.