fix: mount default agent preset so Telegram sessions get the full toolset

[j0935586110-lgtm]

Problem

TelegramBridge creates agents via ctx.agents.create() but never joins an agent preset. Without a preset, each Telegram session resolves its tools / prompt sections / skill catalog against the empty global layer — so only globally-registered tools (e.g. a home-level MCP filesystem) are visible, and every preset-layer tool (bash, read/write/edit, web_search, subagent, todo_write, skill, create_goal, background jobs, …) is missing.

The Web UI path works because dsh-host-apiproxy composes agents with presets.mount(agentCtx, resolvedId) in its setup. This bridge skips that step.

Fix

• inject now also requests agentPresets.
• Both ctx.agents.create() call sites pass a setup that mounts the default preset (standard):

setup: async (agentCtx) => {
  await this.ctx.agentPresets.mount(agentCtx)
}

• Adds @deepseek-ai/dsh-agent-presets as a peer dependency (for the injectable agentPresets service).

Verification

Before the fix, a Telegram session's tool list contained only the home-level mcp__filesystem__* tools (plus approval:policy / sandbox:policy). After the fix, /new sessions see the full standard toolset (bash, read, write, edit, glob, grep, web_search, subagent, todo_write, skill, create_goal, …). tsc compiles cleanly.

[GhitGwen]

Tested — KO on rc.7: bot goes mute after applying the patch.** DSH 0.1.0-rc.7, telegram 0.1.0. Both call sites patched + inject updated. No reply, no error in logs. Revert restores behavior. The diagnosis (sessions resolve against empty global layer without a preset) is confirmed from our side.