feat(mr note create): add --resolvable flag

glab mr note create always opens a resolvable discussion thread, which blocks MR merging when the project requires all threads resolved. Add a --resolvable flag (default true) so that passing --resolvable=false posts a non-resolvable note via the Notes API instead — matching the long-standing behaviour of the deprecated glab mr note -m.

Useful for automation/CI comments that shouldn't require a human to resolve them. Default behaviour is unchanged: omitting the flag still creates a discussion thread.

--resolvable=false is mutually exclusive with --reply and --file (and by extension --line / --old-line), since those operate on discussion threads.

• feat(mr note create): add --resolvable flag for non-resolvable notes

Related Issues

Resolves #8299 (closed)

How has this been tested?

local

Screenshots (if appropriate):