Depone v0.2.0 — security + integrity batch

Security and integrity hardening since v0.1.1:

• Honest verdict labeling: signature_checked / trust_anchor; docs scoped to the tracks that actually verify signatures (#88)
• role_capability_write_scope requires the v109 bound-observation schema; the v106/v107 downgrade is refused (#89)
• role_capability_tool_calls accepted at v109 for combined contracts (#90)
• Advisory-provenance validator now runs as an isolated advisory channel that never changes the verdict (#91)

Depone is consumed by git ref (not PyPI); this release attaches attested build artifacts.