feat(desktop,buzz-acp): add harness-agnostic config bridge and setup-listener mode

[wpfleger96]

This PR adds a harness-agnostic config bridge that detects unconfigured managed agents and spawns buzz-acp in a minimal setup-listener mode instead of the normal agent pool.

Before this, a managed agent missing its provider, model, or credential keys would fail silently or crash-loop on spawn. Users had no indication what was missing or where to configure it.

• Add readiness.rs to desktop/src-tauri/src/managed_agents: EffectiveAgentEnv resolver, Requirement enum (NormalizedField / EnvKey / CliLogin), and agent_readiness() predicate; covers buzz-agent, goose, claude, codex runtimes with 11 unit tests
• Add requiredCredentialEnvKeys() to personaDialogPickers.tsx mapping runtime+provider to required env keys; EnvVarsEditor gains a requiredKeys prop rendering locked amber rows at top with a Required badge when empty
• Add isMissingRequiredDropdownField() in personaDialogPickers.tsx wired to useAgentConfigSurface().data?.normalized.{model,provider}.isRequired; EditAgentDialog shows required * labels on model/provider dropdowns sourced from the config-bridge normalized surface (single source of truth — flows from KnownAcpRuntime.required_normalized_fields → read_config_surface() → NormalizedField.isRequired)
• Add setup_mode.rs to buzz-acp: SetupPayload deserialization, run_setup_listener() event loop — connects to relay, subscribes channels (mentions-only), applies author gate, and replies with a surface-correct nudge naming each missing requirement; 30s per-channel cooldown and per-event-id dedup; 6 unit tests
• Wire early branch in buzz-acp tokio_main: if BUZZ_ACP_SETUP_PAYLOAD is set, enter setup mode and skip the agent pool entirely
• Wire readiness check in spawn_agent_child (runtime.rs): calls resolve_effective_agent_env() + agent_readiness() after resolving runtime_meta; if NotReady, serializes requirements as BUZZ_ACP_SETUP_PAYLOAD JSON

[wpfleger96]

PR #1411 — CreateAgentDialog local-mode readiness gate

This PR brings Create up to Edit's block-save guarantee: a local-mode buzz-agent/goose can no longer be created with a missing dialog-fixable credential that would crash-loop at spawn. Screenshots below walk the gate firing and clearing.

Create — buzz-agent, empty provider → blocked

Provider marked required; Create button disabled until a provider is chosen.
{{01-create-buzzagent-empty-provider-blocked}}

Create — buzz-agent + anthropic, empty model → blocked

Model marked required; Create stays disabled until a model is set.
{{02-create-buzzagent-empty-model-blocked}}

Create — missing required credential → amber row + blocked

ANTHROPIC_API_KEY surfaced as a required row so the user can see exactly what to add.

Create — all required satisfied → enabled

Provider, model, and credential present; Create button enabled.
{{04-create-all-required-satisfied-enabled}}

Create — CLI-login runtime → provider/model not required

claude/codex authenticate via CLI login, so provider/model aren't required and Create stays enabled.
{{05-create-cli-login-runtime-no-provider-required}}

Edit — shared extracted provider/model fields

Edit's provider/model fields now come from the shared personaProviderModelFields component; appearance is unchanged.
{{07-edit-dialog-extracted-fields}}

Create — goose, empty provider → blocked

The second provider-selection runtime is gated identically to buzz-agent.
{{08-create-goose-empty-provider-blocked}}

[wpfleger96]

PR #1411 — CreateAgentDialog local-mode readiness gate

This PR brings Create up to Edit's block-save guarantee: a local-mode buzz-agent/goose can no longer be created with a missing dialog-fixable credential that would crash-loop at spawn. Screenshots below walk the gate firing and clearing.

Create — buzz-agent, empty provider → blocked

Provider marked required; Create button disabled until a provider is chosen.

Create — buzz-agent + anthropic, empty model → blocked

Model marked required; Create stays disabled until a model is set.

Create — missing required credential → amber row + blocked

ANTHROPIC_API_KEY surfaced as a required row so the user can see exactly what to add.

Create — all required satisfied → enabled

Provider, model, and credential present; Create button enabled.

Create — CLI-login runtime → provider/model not required

claude/codex authenticate via CLI login, so provider/model aren't required and Create stays enabled.

Edit — shared extracted provider/model fields

Edit's provider/model fields now come from the shared personaProviderModelFields component; appearance is unchanged.

Create — goose, empty provider → blocked

The second provider-selection runtime is gated identically to buzz-agent.