skillscript-runtime v0.27.2

Upgrade impact: none (additive). Docs, help-content, one error message, and CLI onboarding copy; no runtime behavior change.

Final pre-launch pass — make every surface tell the truth and steer safely.

• # OnError: is now presented as inert/deprecated everywhere it appears, instead of contradicting itself. It parses but is not wired in the runtime (the named fallback never fires), so a skill relying on it has no error handling. Fixed: the help({topic:"frontmatter"}) entry (was "error-handler skill invoked when an op fails"), the ${ERROR_CONTEXT} ambient table (was "Inside else: and # OnError:"), the $ json_parse line, and — the sharpest one — the MissingSkillReferenceError runtime remediation message, which previously told users to wire # OnError: as the fix. All now point at a target-level else: block or an op-level (fallback: ...). language-reference.md re-rendered from atoms with a "Deprecated: parsed but not wired — removal planned for v0.28" section. The grammar removal itself is deferred to v0.28 (a parser/compile/runtime change kept off the launch path).
• Recursion help correction completed. 0.27.1 fixed one of two "default 5" strings in the composition topic; the execute_skill section still contradicted the Limits section. Both now read default 10 (matching DEFAULT_MAX_RECURSION_DEPTH).
• Onboarding: --host 0.0.0.0 kept as the deliberate default (container-native: 127.0.0.1 is unreachable across a container namespace, so a client like NanoClaw needs all-interfaces) — now with a caption on the init hint, getting-started, and CLI help examples: binds all interfaces so a containerized client can reach it; on a shared/untrusted host use --host 127.0.0.1 or set SKILLSCRIPT_EVENT_INGRESS_AUTH_TOKEN. (Requiring the token when binding off-localhost is tracked as a v0.28 behavioral hardening.)
• EACCES install note added to the README + docs getting-started: npm install -g may fail with EACCES on a root-owned global prefix — re-run with sudo or use an nvm-style prefix. Standard npm behavior, not a Skillscript issue.