docs: skills/ilo/ilo-builtins-io.md uses pst as canonical (closes ILO-80)

[danieljohnmorris]

Summary

• ilo-builtins.md was split into category files; the HTTP section in ilo-builtins-io.md already used pst as the builtin name but did not explicitly call out that post (pre-0.12.0) is not accepted
• Added an inline note on the pst line: (pst is the canonical name since 0.12.0; the old name post is not accepted.)
• PRs Add rand alias for rnd #581/Add muscle-memory aliases: post, upper, lower, capitalize #589 (post alias) have not landed, so no alias mention is included
• No other stale lowercase post references found in skills/; all uppercase POST occurrences are HTTP method names and are correct

Test plan

• Load ilo-builtins-io.md in a skill context and verify agent uses pst not post
• Confirm no other lowercase post builtin references remain: grep -rn 'post ' skills/

🤖 Generated with Claude Code

[codecov]

❌ 1 Tests Failed:

Tests completed	Failed	Passed	Skipped
7587	1	7586	0

View the top 1 failed test(s) by shortest run time

ilo::skill_md::body_is_thin_bootstrap

Stack Traces | 0.006s run time

thread 'body_is_thin_bootstrap' (65418) panicked at tests/skill_md.rs:254:5:
SKILL.md body is 12135 bytes; bootstrap shape should stay well under 8 KB
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

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