CB-618: one charter file, and agent files need a name:

Two defects in CB-617 that only a live spawn could find. Both were shipped
green: every test passed because every test read the argv we built, and none
ran the binary that has to accept it.

1. Claude Code refuses to start when both --append-system-prompt and
   --append-system-prompt-file are on the command line:

     Error: Cannot use both --append-system-prompt and
     --append-system-prompt-file. Please use only one.

   CB-617 put the role charter on the file flag and left the reply charter on
   the inline flag, so every Claude-profile spawn with a role charter died at
   launch. The pane exited on its own and bridged reported it as
   spawn_timeout ("did not reach injectable state within 20000ms"), which
   hides the real cause.

   Both charters now go in the one file, role charter first and reply charter
   last — last is where the reply rule must sit, because it is the rule that
   must survive. A member with only a reply charter keeps the proven inline
   flag, which is also the only form that reaches a member with no repo
   checkout.

2. A Claude Code agent definition needs `name:` in its frontmatter. Ours had
   only `description:`, so the files were skipped and --agent architect failed
   with "not found. Available agents: claude, Explore, ...". Added to all
   three. The OpenCode files take their name from the filename and are
   unchanged.

Checked on this host, in this repo, with the real binary:

  claude --model claude-sonnet-5 --agent architect \
    --append-system-prompt-file /tmp/combined.md -p '...'
  -> ROLEOK, REPLYOK, yes

so the agent definition, the role charter and the reply charter all compose.

The updated test now asserts the constraint that actually binds: with a role
charter present, --append-system-prompt must be absent, and the file must open
with the role charter and end with the reply charter.

874 tests pass.

bridged/src/main/java/dev/ltms/bridged/member/ClaudeCodeLauncher.java

@@ -279,9 +279,15 @@ public final class ClaudeCodeLauncher extends HerdrPeerLauncher {
      * single inline argv element — herdr refuses to shell-encode a multi-line argument
      * ({@code invalid_agent_argument}). It is written to a temp file instead and mounted with
      * {@code --append-system-prompt-file}, which this host confirms Claude Code accepts for a
-     * multi-line file. The reply charter is always exactly one line and demonstrably encodes, and it
-     * must reach a member with no repo checkout (nowhere to put a file), so it keeps its inline
-     * {@code --append-system-prompt} delivery.
+     * multi-line file.
+     *
+     * <p>CB-618: Claude Code refuses to start when BOTH {@code --append-system-prompt} and
+     * {@code --append-system-prompt-file} are on the command line ("Cannot use both ... Please use
+     * only one"), so the two charters can never travel on separate flags. When both are present they
+     * are concatenated into the one file, role charter first and reply charter last — last is where
+     * the reply rule must sit, because it is the rule that must survive. When only the reply charter
+     * is present it keeps its proven inline {@code --append-system-prompt} delivery, which is also
+     * the only form that reaches a member with no repo checkout.
      */
     private List<String> argvWithBridge(BridgedConfig.Profile cfg, LaunchSpec spec) {
         String roleCharter = nonBlank(spec.roleCharter());
@@ -298,10 +304,10 @@ public final class ClaudeCodeLauncher extends HerdrPeerLauncher {
             argv.add(mcpJson);
         }
         if (roleCharter != null) {
+            String combined = replyCharter == null ? roleCharter : roleCharter + "\n\n" + replyCharter;
             argv.add("--append-system-prompt-file");
-            argv.add(writeRoleCharterFile(roleCharter).toString());
-        }
-        if (replyCharter != null) {
+            argv.add(writeCharterFile(combined).toString());
+        } else if (replyCharter != null) {
             argv.add("--append-system-prompt");
             argv.add(replyCharter);
         }
@@ -325,10 +331,10 @@ public final class ClaudeCodeLauncher extends HerdrPeerLauncher {
      * reads this file (the spawned peer) outlives this JVM call and there is no spawn-scoped teardown
      * hook to delete it synchronously.
      */
-    private static Path writeRoleCharterFile(String roleCharter) {
+    private static Path writeCharterFile(String charterText) {
         try {
             Path file = Files.createTempFile("bridged-role-charter-", ".md");
-            Files.writeString(file, roleCharter);
+            Files.writeString(file, charterText);
             file.toFile().deleteOnExit();
             return file;
         } catch (IOException e) {