feat(orchestrate): separate peer collaboration from execution

[Tryanks]

Orchestrate previously treated high-level consultation as execution and represented reasoning efforts as duplicate model profiles. This change separates peer discussion from task dispatch and lets the lead choose an executor's effort for each call.

• Add a read-only collaborate tool for independent decision discussions. Keep concrete work on dispatch, and prefer tcode Orchestrate across providers over provider-native subagents.
• Bundle Astra and Fable 5.1 as collaborators, restricted to medium/high. Give a consulted peer its own collaboration guidance; the main thread receives workflow instructions and only other peers' self-concepts.
• Bundle Sol and Opus 5 as executors. Expose supported reasoning efforts from provider catalogs, validate each call, and guide Sol selection from medium for routine work through max for difficult problems.
• Keep one entry per provider/model across both lists. Migrate legacy effort tiers and model versions, retain custom guidance and routing choices, and remove the bundled Sonnet entry.
• Make collaboration switches independent of main-model selection. Update the settings UI, English/Chinese strings, design documentation, and official model-guidance references.

Validation:

• Full workspace suite: 1006 passed, 4 ignored; subsequent Orchestrate regression checks also pass, including a lead that continues orchestrating with all collaboration switches off.
• cargo fmt --all --check, workspace Clippy with -D warnings, and cargo build pass. The local debug build retains the existing macOS unwind-table linker warning and block future-compatibility notice.
• Native UI smoke check with an isolated data directory: model lists, reasoning choices, and duplicate exclusions.