feat: merge oo-cli and extend library with Calendar/CRM/subtasks/files

- Add Calendar helpers (ListCalendars/ListEvents/AddEvent/DeleteEvent)
- Add CRM helpers: contacts, opportunities, cases, CRM tasks, history notes
- Add project-task extras (ListTasks/ListAllTasks/GetTaskByID/AddTask/
  AddSubtask/UpdateTaskStatus/DeleteTask, GetProjectByID)
- Add UploadOpportunityFile (multipart) and SelfUserID caching
- Introduce Defaults struct, SetDefaults, GetEnvironmentDefaults;
  GetEnvironmentCredentials now accepts ONLYOFFICE_HOST/NAME/PASSWORD aliases
- Add public Authenticate() helper that eagerly primes the token
- Bundle Cobra CLI at cmd/oo-cli with full command surface
  (calendar, tasks, subtasks, CRM, applications-sync); CLI-only deps
  (cobra, godotenv) kept out of the library surface
- Add httptest-based unit tests for form/multipart helpers
- Docs: CHANGELOG, AGENTS, .env.example, README updates for v0.3 features

Consolidates the standalone eSlider/oo-cli tool into this canonical Go
module (see eSlider/inventar ASR-0008).

Made-with: Cursor

AGENTS.md

@@ -0,0 +1,23 @@
+# AGENTS — go-onlyoffice
+
+Canonical Go client for OnlyOffice Workspace (Projects + Calendar + CRM) and the `oo-cli` command.
+
+## Topology
+
+- **Library (root package `onlyoffice`)** — `onlyoffice.go`, `httpx.go`, `calendar.go`, `crm.go`, `tasks_extra.go`, `files.go`. Pure stdlib + `google/go-querystring`; no UI, no dotenv.
+- **CLI (`cmd/oo-cli` + `internal/cli`)** — Cobra wrapper that loads `.env` via `godotenv` at startup. CLI-only deps (`spf13/cobra`, `joho/godotenv`) must stay out of the library surface.
+- **Applications sync (`internal/applications`)** — README/CRM bridge, consumes the library.
+
+## Rules
+
+- Library must never call `godotenv.Load()` — the CLI does that.
+- New endpoints go into the library first; CLI commands are thin wrappers.
+- No secrets in the repo; use `.env` (gitignored). Commit `.env.example` only.
+- Prefer httptest-based unit tests (see `httpx_test.go`); integration tests (`client_test.go`) auto-skip without `ONLYOFFICE_URL`.
+- Follow SemVer on tags; this repo is tagged at GitHub under `git@github.com:eSlider/go-onlyoffice.git`.
+
+## Related
+
+- [`eSlider/inventar`](https://git.produktor.io/eSlider/inventar) — ASR/ADR (see ASR-0008 Go library module conventions).
+- [`eSlider/inventar-sync`](https://git.produktor.io/eSlider/inventar-sync) — OnlyOffice → Gitea issue sync, consumes this library.
+- [`produktor.io/vidarr`](https://git.produktor.io/produktor.io/vidarr) — legacy consumer being migrated from `pkg/onlyoffice` to this module.