release: 3.3.6 — forbid manual steps in implementer loop

[ncheaz]

The previous BP allowed manual checkboxes if tagged [manual], which guaranteed a BLOCKED_HANDOFF on every encounter. Tighten guidance so operator-only items live in a dedicated post-loop section and rewrite pre-scan rule #6 to enforce placement instead of just flagging.

OPENSPEC-RALPH-BP.md:

• Add new section "Human-loop boundary (no manual steps mid-loop)" that promotes the pre-existing one-liner into a first-class rule with rationale, placement rules, automate-instead-of-manual decision table, section template for the post-loop operator section, and a worked BAD-vs-GOOD refactor example using the H1 probe from fix-docs-tailwind-cascade-layers task 4.2.
• Anti-patterns: add explicit bullet forbidding manual checkboxes in the implementer task list, with the "guaranteed BLOCKED_HANDOFF" reasoning.
• Pre-scan rule Iterate on oepsnpec and ralph wiggum best practices #6: rewrite from "tag manual tasks with [manual]" to a true placement rule with three concrete failure conditions (marker, stop-condition phrasing, human-only Done-when evidence) plus explicit remediation paths (automate or relocate).
• Artifact requirements: cross-reference the new section so the existing "human/operator work is outside the checkbox path" line is enforceable.

AGENTS.md item 6: lockstep update with the same wording and cross-reference.

package.json: bump 3.3.5 → 3.3.6 (patch — guidance change, no API change).

Tests: 160/160 pass (jest + bats), exit 0.