chore: tidy comments that repeat the code or no longer match it

- Comments that only restate a name (sgr, fg, mdLink, the repo provider's starred and current-repo notes) are gone.
- Stale ones match the code again: the repo package covers plain env files too, Launch runs argv, closeVersions no longer claims to move the cursor, and Check's fallback says why rather than naming a state no release had.
- The doc for versionString was attached to pseudo; the backtick in SourcesView's doc was a string-concatenation leftover; openFailed's doc was garbled.
- recentReleases sits next to latest, its user.
- .gitignore drops the Go template's boilerplate and patterns for files this project doesn't make.

internal/ui/app/sharefiles.go

@@ -304,7 +304,7 @@ func (m *Model) handleShareOpened(msg shareOpenedMsg) tea.Cmd {
 }
 
 // openFailed says why a share link couldn't be decrypted, in a popup
-// where its offer was: its first line (wrapped), or with whole all of it
+// where its offer was: its first line (wrapped), or, with whole, all of it
 // (Key Vault's refusals say what to check on later lines). From there,
 // the key's secret can be gone to: its version, which may be disabled.
 func (m *Model) openFailed(s share.Sealed, err error, whole bool) {