Fix zsh capture script exit code and redundant compinit

The capture script always returned exit code 2 because `return 0` inside
the piped while-loop only exits the subshell, not the script. Since
carapace's ActionExecCommand treats non-zero exits as errors and skips
the output callback, this silently broke the zsh bridge on every
invocation. Changed the unconditional `return 2` to `return 0`.

Also merged the redundant double compinit call into a single call with
the custom dump path, and fixed stray whitespace on the source line.

Added deviation comments marking where this vendored copy diverges from
upstream (Valodim/zsh-capture-completion).

Assisted-by: Crush:glm-5.2

Author: rsteube-bot

third_party/github.com/Valodim/zsh-capture-completion/capture.zsh

@@ -22,10 +22,10 @@ setopt rcquotes
 PROMPT=
 
 # load completion system
+# carapace-bridge: use dedicated dump path and source user .zshrc for fpath changes
 oldfpath="$fpath"
-autoload -U compinit && compinit
-compinit -d "${CARAPACE_BRIDGE_CONFIG_HOME:-$HOME/.config}/carapace/bridge/zsh/.zcompdump_capture"
-source      "${CARAPACE_BRIDGE_CONFIG_HOME:-$HOME/.config}/carapace/bridge/zsh/.zshrc"
+autoload -U compinit && compinit -d "${CARAPACE_BRIDGE_CONFIG_HOME:-$HOME/.config}/carapace/bridge/zsh/.zcompdump_capture"
+source "${CARAPACE_BRIDGE_CONFIG_HOME:-$HOME/.config}/carapace/bridge/zsh/.zshrc"
 [[ "$oldfpath" != "$fpath" ]] && compinit # second call to adopt any changes to fpath
 
 
@@ -138,4 +138,5 @@ while zpty -r z; do :; done | while IFS= read -r line; do
     (( tog )) && echo -E - $line
 done
 
-return 2
+# carapace-bridge: was `return 2` upstream, which always exited non-zero and broke ActionExecCommand
+return 0