Extract aps/gps logic into bin/ scripts

[ikuwow]

Why

The aps / gps functions in .functions have grown large. Moving the bulk of the logic into standalone bin/ scripts makes them easier to shellcheck and edit on their own.

Design

Both commands need to export shell environment variables (AWS_PROFILE, GC_ACTIVE_CONFIG) into the parent shell, which a subprocess script cannot do. So a full move to bin/ is impossible. Instead, the heavy lifting lives in bin/aps and bin/gps, and .functions keeps only thin wrappers responsible for the export.

• Both commands already persist their selected state on disk (~/.aws/current_profile, gcloud active_config), so the wrapper just re-reads that file after the script returns.
• The wrapper calls command aps "$@" to bypass the function and reach the script on $PATH.

The original if [ ! "$(command -v aps)" ] guards in .functions are removed: once bin/aps is on $PATH they would be permanently false and the wrapper would never be defined.

deploy.sh already auto-symlinks any 0755 file under bin/ via find, so no changes are needed there.

Verification

• shellcheck bin/aps bin/gps clean
• bash -c 'PATH=$HOME/bin:$PATH; source ~/.functions; aps --list; echo AWS_PROFILE=$AWS_PROFILE' confirmed AWS_PROFILE is set correctly via the wrapper
• Same flow for gps --list confirmed GC_ACTIVE_CONFIG is set
• aps --clear clears AWS_PROFILE to empty string and removes ~/.aws/current_profile
• aps --help / gps --help print help and exit (no env change beyond idempotent re-export — see Notes)
• Interactive fzf selection paths (aps <query>, aps, gps <query>, gps) verified in a real shell
• SSO session-expired case (aws sts get-caller-identity Account ID not 14 digits) triggers aws sso login

Notes

• The SSO login check inside bin/aps runs as AWS_PROFILE=$profile aws ... since export does not propagate to the parent (and the script does not need to set the env for itself).
• For read-only commands (--help, --list), the wrapper still re-exports AWS_PROFILE from the persisted file unconditionally. This is idempotent against the persisted state so there is no functional issue. Use aps --clear to actually drop the export.

[ikuwow]

Closing: #233 rewrites gps as a stateless CLOUDSDK_CORE_PROJECT switcher, which removes the on-disk state this extraction was designed around. The gps half would need a full redo once #233 lands, and the standalone value of the refactor (easier shellcheck) does not justify that rework for a personal repo. If extraction is still wanted for aps alone later, it can be redone against the post-#233 shape.