test(keybindings): cover cj/jump-open-var and the jump-commands wiring

Two test files for keybindings.el. cj/jump-open-var gets full N/B/E
coverage (6 tests): existing-file happy path, plus error paths for
unbound symbol, nil value, non-string value, empty string, and missing
file. The smoke file for the auto-generated cj/jump-to-NAME commands
asserts that each spec entry has an fbound command, that the command
is bound in cj/jump-map at the spec's key, that calling each command
invokes cj/jump-open-var with the spec's var, and that cj/jump-map is
mounted under cj/custom-keymap at "j".

The test fixture variable is declared at top level. If it were
let-bound inside a test under lexical-binding, the let would create a
lexical binding that shadows the dynamic one. The production code's
symbol-value would then miss what setq writes. find-file is mocked at
the boundary so the existing-file test doesn't actually open a buffer.

10 tests pass. No production change in keybindings.el.

0 files changed, 0 insertions, 0 deletions