[spec] t27mcp/visual_output.t27 -- every answer carries a T27F visual, by host #10531

Goal

Write down once, as specs/t27mcp/visual_output.t27, the rule that every answer explaining a spec, a flow, numbers or a piece of work carries one visual drawn the T27F way: where it goes per host, when a tool's SVG is embedded as is and when it is redrawn, and what makes a visual wrong.

Why this matters

Both consumers (the MCP host and the agents) read one rule instead of two hand copies (T27F, gHashTag/trinity#1648).

Source of truth

specs/t27mcp/visual_output.t27

Deliverable

PR #10504 (spec + seal).

Done when

Spec parses, its tests pass, seal saved; required checks green.

How to verify

./target/release/t27c test-report specs/t27mcp/visual_output.t27

Risks

None beyond the spec itself; the change is one spec and its seal.

Links (issue, PR, ADR)

PR #10504; T27F RFC gHashTag/trinity#1648; see also draft PR #10510, which carries the same file.

User Scenarios

• Given the repository has no specs/t27mcp/visual_output.t27 file, When an agent creates that spec with the T27F visual-output rules and runs the compiler test command, Then the spec parses, its tests pass, and the seal is saved.

Requirements

• FR-001: The file specs/t27mcp/visual_output.t27 MUST exist and be a valid .t27 spec.
• FR-002: The spec MUST codify the rule that every answer explaining a spec, a flow, numbers, or a piece of work carries one T27F visual, including where it goes per host, when a tool's SVG is embedded as-is versus redrawn, and what makes a visual wrong.
• FR-003: Running ./target/release/t27c test-report specs/t27mcp/visual_output.t27 MUST exit 0 and produce a passing test report.
• FR-004: The spec's seal MUST be generated and saved alongside the spec.

Success Criteria

• ./target/release/t27c test-report specs/t27mcp/visual_output.t27 exits 0
• 1 spec file created at specs/t27mcp/visual_output.t27
• 1 seal file saved for specs/t27mcp/visual_output.t27
• All required checks green

Boundary

• specs/t27mcp/visual_output.t27