v0.9.0 2.20: let Fleet profiles save provider model and thinking

[Hmbown]

Parent: #4111
Source: CODEWHALE_0_8_68.md Section 2.20

Extend the Fleet profile schema and /fleet setup so users can save the actual route for each agent profile: provider, concrete model, and thinking/reasoning effort.

Where:

• crates/tui/src/fleet/profile.rs (AgentProfileToml)
• crates/config/src/lib.rs (FleetProfile)
• crates/tui/src/tui/views/fleet_setup.rs
• crates/tui/src/fleet/worker_runtime.rs (resolve_fleet_route, effective_fleet_model)

What:

• Add safe, non-secret provider, model, and thinking/reasoning_effort fields to FleetProfile and the TOML loader.
• /fleet setup configures role, model provider, concrete model, thinking tier, tools/posture, and inheritance.
• inherit main/operator stays explicit, not the only behavior.
• Wire through receipts/rows: resolved provider, resolved model, thinking, and route_source.

Example profiles must round-trip:

• scout: DeepSeek V4 Flash + max thinking.
• implementer: GLM 5.2.
• reviewer: DeepSeek V4 Pro + max thinking.

Acceptance:

• TOML -> AgentProfile -> resolved route works for all examples.
• /fleet setup can set provider + model + thinking.
• cargo test -p codewhale-tui fleet passes.
• reasoning_effort is not empty when a profile pins thinking.

[Hmbown]

Per #4175: saved provider/model/thinking fields belong on AgentProfile; Fleet roster binds roles → those profiles. Workflow must not duplicate route config (#4177). UI fix for #4093 depends on this schema.

[Hmbown]

Scope note (consolidating the duplicate #4195): #4181 (merged) landed the provider+model half of this. The remaining half is thinking / reasoning-tier persistence — a reasoning field on AgentProfile/FleetProfile + honoring it at runtime. Key seam: crates/tui/src/auto_reasoning.rs:22-24 HARD-CAPS any sub-agent to ReasoningEffort::Low, so a saved thinking tier would be ignored for sub-agents today — un-cap it to honor the profile's tier (keep Low only when unset). This is the "make sub-agents use more test-time compute" knob. Sequenced after #4193 (shares subagent/mod.rs) and #4136 (canonical AgentProfile).