## 1. Create addnote command

- [x] 1.1 Create `client/cmd/addnote.go` with `addnoteCmd` using `ExactArgs(1)`, `--tags` flag, and `RunE` calling `submitNote()`
- [x] 1.2 Move `submitNote()` function from `client/cmd/add.go` to `client/cmd/addnote.go`

## 2. Revert root command to standard Cobra behaviour

- [x] 2.1 Remove `ArbitraryArgs`, custom `RunE` logic, and `--tags` flag from root command in `client/cmd/root.go`
- [x] 2.2 Remove custom usage template and `isRootCmd` template function — let Cobra use its default template
- [x] 2.3 Set root command to show help when called with no args (standard Cobra `RunE` returning `cmd.Help()` or nil)

## 3. Update examples and help text

- [x] 3.1 Update `client/cmd/examples.go` to show `kb addnote` syntax instead of `kb "text"` shorthand
- [x] 3.2 Update root command `Long` description to remove reference to note shorthand

## 4. Update tests

- [x] 4.1 Remove implicit note shorthand tests from `client/cmd/root_test.go` (`TestRootCmd_SingleWordRejected`, `TestRootCmd_MultipleWordsNotRejected`)
- [x] 4.2 Add test for `addnote` command (verify it wires up correctly, takes exactly one arg)
- [x] 4.3 Add test that root command with unknown args returns an error (standard Cobra behaviour)
- [x] 4.4 Verify `addfile` tests still pass (no changes expected)

## 5. Build and verify

- [x] 5.1 Run `go build` and verify all commands appear in `kb --help`
- [x] 5.2 Run `go test ./...` and verify all tests pass
- [x] 5.3 Verify `kb addnote --help` shows correct usage line and flags
- [x] 5.4 Verify `kb addfile --help` is unchanged