Adopt the modern-di integration kit

[lesnik512]

Summary

modern-di 2.28.0 shipped modern_di.integrations — framework-agnostic primitives that formalize what this package's FromDI/@inject already hand-roll. This swaps the hand-rolled internals for kit calls. No public-API change; zero test-file changes.

Seventh of 13 planned adapter conversions (after starlette 2.2.0, fastapi 2.10.0, litestar 2.13.0, aiohttp 2.2.0, flask 2.1.0, faststream 2.10.0). First conversion where the kit's Layer 1 (bind/classify_connection) has nothing to attach to at all — a CLI invocation has no connection object analogous to a web Request or broker StreamMessage; the only per-invocation object is Click's own typer.Context, which @inject already threads through natively. This is a Layer-2-only conversion.

• _FromDI deleted; FromDI = integrations.from_di.
• _parse_inject_params keeps its hand-rolled typer.Context-detection scan (the kit has no equivalent for this typer-specific concern) but delegates marker-finding to integrations.parse_markers.
• _resolve_di_params deleted; inject's wrapper calls integrations.resolve_markers directly.
• Dead imports removed: dataclasses, providers (this repo has no module-level connection provider, unlike every prior web/broker conversion), T_co.
• architecture/injection.md promoted; architecture/scopes.md deliberately left untouched (describes container hierarchy behaviorally, names none of the changed internals).
• Bumps the modern-di floor to >=2.28.0,<3.

Test plan

• just test-ci — 100% line coverage, all 11 tests passing, zero test-file changes
• just lint-ci — ruff, ty, check-planning all clean
• Per-task spec + quality review (4 tasks, all approved)
• Whole-branch review (approved; one minor, practically-unreachable finding noted — the hand-rolled Context-detection scan doesn't explicitly skip a return type hint, only reachable if a command were annotated -> typer.Context, which no real Typer command does)