feat(cli): --json for members, du and public-link create/update

Scripts, the acceptance suite among them, can now read a link's id,
role, password flag and expiry, and a folder's size and item count,
instead of parsing the human-readable lines.

crates/pdfs-cli/src/main.rs

@@ -1556,9 +1556,13 @@ fn cmd_versions(action: VersionCmd) -> Result<()> {
 }
 
 fn cmd_members(path: PathBuf) -> Result<()> {
-    match control_request(CtlRequest::ListShare {
+    let response = control_request(CtlRequest::ListShare {
         path: path_arg(&path)?,
-    })? {
+    })?;
+    if emit_json(&response)? {
+        return Ok(());
+    }
+    match response {
         CtlResponse::Share { entries, link } => {
             if entries.is_empty() {
                 println!("No members or pending invitations.");
@@ -1625,6 +1629,7 @@ fn cmd_public_link(action: PublicLinkCmd) -> Result<()> {
             password,
             expires,
         })? {
+            response if emit_json(&response)? => {}
             CtlResponse::PublicLink { link } => {
                 println!("{}", link.url.as_deref().unwrap_or("(no url returned)"));
             }
@@ -1646,6 +1651,7 @@ fn cmd_public_link(action: PublicLinkCmd) -> Result<()> {
             password: link_change(password, no_password),
             expires: link_change(expires, no_expiry),
         })? {
+            response if emit_json(&response)? => {}
             CtlResponse::PublicLink { link } => {
                 println!("{}", link.url.as_deref().unwrap_or("(no url returned)"));
             }
@@ -3048,9 +3054,13 @@ fn cmd_copy(sources: Vec<PathBuf>, new_parent: PathBuf) -> Result<()> {
 }
 
 fn cmd_du(path: PathBuf) -> Result<()> {
-    match control_request(CtlRequest::FolderSize {
+    let response = control_request(CtlRequest::FolderSize {
         path: path_arg(&path)?,
-    })? {
+    })?;
+    if emit_json(&response)? {
+        return Ok(());
+    }
+    match response {
         CtlResponse::FolderSize { size, items } => {
             let noun = if items == 1 { "item" } else { "items" };
             println!(

docs/CLI.md

@@ -190,8 +190,9 @@ commands are for scripts and for cases where the mount is not available.
 ## Scripting with `--json`
 
 The global `--json` flag makes query commands print JSON: `status`, `ls`, `pins`, `sync list`,
-`devices list`, `locations`, `transfers`, `activity`, `trash` and `cache inspect`. Commands that change
-something keep their human-readable output; check their exit code.
+`devices list`, `locations`, `transfers`, `activity`, `trash`, `cache inspect`, `members` and `du`.
+`public-link create` and `public-link update` print the link they made or changed. Other commands
+that change something keep their human-readable output; check their exit code.
 
 ```bash
 pdfs --json status | jq -r '.mount.mountpoint'