fix: sync generated hive-forge CLI docs with their clap source strings

Same bug as the swarmctl/hivectl fix, a third instance argus's review
didn't name but nix/checks.nix's hive-forge-docs freshness check (same
pattern as hivectl-docs/swarmctl-docs) caught in CI: the earlier
Contractions/Foreign/Auto batches edited docs/tools/forge-cli.md
directly instead of the clap #[arg(...)]/doc-comment strings in
hive-forge/src/main.rs and hive-forge/src/verbs/*.rs.

Applied the same 13 wording changes to source that the earlier commits
already made to the generated .md, matched 1:1 against
'git diff origin/main HEAD -- docs/tools/forge-cli.md' rather than
guessed. Several source doc comments feed two rendered sections each
(e.g. reaction.rs's one Add-variant doc renders under both
'issue reaction add' and 'pr reaction add', since both subcommands
share the same enum) -- one source fix, two generated-doc fixes.

Regenerated from the now-fixed source and confirmed byte-identical to
what's already committed (diff exit 0) -- source and generated output
are back in sync, same as the swarmctl/hivectl fix.

cargo clippy -p hive-forge --all-targets -- -D warnings and
scripts/check-doc-refs.sh both clean.

hive-forge/src/verbs/repo_create.rs

@@ -27,7 +27,7 @@ pub struct Args {
     /// Create the repo as private (default: public).
     #[arg(long)]
     private: bool,
-    /// Default branch name (e.g. `main`). Only takes effect with `--auto-init`.
+    /// Default branch name (for example `main`). Only takes effect with `--auto-init`.
     #[arg(long = "default-branch")]
     default_branch: Option<String>,
     /// Create under this organisation instead of your own namespace.