Buzz Desktop v0.5.1

• perf(desktop): move observer-feed archive and decrypt commands off main thread (#3415) (294c8c821)
• fix(desktop): preserve shared agent fidelity (#3553) (f7a3988ba)
• feat(agent): route Claude/GPT model families to their native gateway wire (#3538) (6438dedf8)
• Refine community invite limits (#3529) (24d90d128)
• feat(agent): fix Anthropic prompt caching with Databricks (+ MCP proxy/TLS passthrough) (#3463) (c405ad1d4)
• feat: add explicit entry for claude-opus-5 in model config (#2831) (90e058ebf)
• fix(desktop): clear stale thread new-message pill (#3411) (55a3ed7b9)
• fix(ci): ratchet file sizes against the base tree (#3352) (9227bdf58)
• feat(desktop): apply WebKit rendering workarounds at startup on Linux (#3271) (3ece4461d)
• fix(desktop): stabilize flaky DM expansion E2E ordering assertions (#2004) (913d564ce)
• fix(desktop): paint community rail full height (#3382) (1d3b810ad)
• feat(desktop): add custom harness inline from agent dialogs (#3252) (b0503d80c)
• feat(desktop): refine agent catalog sharing (#2439) (a35771fc4)
• fix(desktop): keep drafts out of the Inbox All view (#3217) (3afa129ee)
• fix(desktop): restore the inbox icon in the sidebar (#3341) (00ede2e7a)
• fix(desktop): gate codex-acp on a minimum supported version (#3254) (4e3998f36)
• feat(cli): add users set-status command for NIP-38 profile status (#3253) (60158fce3)
• fix(composer): scope multiline block formatting (#3246) (5457c947a)