feat(telega-config): guard launcher with a helpful message when telega is missing

Without the guard, both `C-; G' and the dashboard Telegram icon
trigger telega's autoload stub directly.  When the package isn't
installed yet the user sees `Cannot open load file: telega' in
`*Messages*' with no hint about what to do.

Wrap the launcher in `cj/telega' that checks `featurep' /
`locate-library' first.  If telega is present, delegate to it.
Otherwise signal a `user-error' pointing at `scripts/setup-telega.sh'
and the manual `M-x package-install RET telega' fallback.  Rebind
`C-; G' and the dashboard "g" key + Telegram icon callback to the
wrapper.

Two new tests in `test-telega-config.el' cover the wrapper paths
(absent -> user-error with the recovery hint; present -> delegates
to `telega') alongside the updated binding assertion.

0 files changed, 0 insertions, 0 deletions