feat(sessions): make pinning every tab name an opt-in setting

Add pinCliSessionName (synced, default OFF), re-read at each spawn and respawn.
Off keeps the #457 behaviour; on pins every non-blank tab name as --name.
Update the docs, JSDoc and changeset that stated the old rule.

.changeset/cli-session-name-matches-tab.md

@@ -2,4 +2,4 @@
 'aicodeman': minor
 ---
 
-A Claude session is now launched with `--name <tab name>` for every tab, not only for ones you renamed. Claude Code's prompt-box label, `/resume` entry and its remote session list used to show Claude's own generated title (for example "Git indicator guard test and teardown flake") for a tab that Codeman called `w4-Codeman`; they now read the same as the tab. A rename or an auto-name reaches the CLI at its next spawn.
+New App Settings option, "Pin tab names on the CLI" (off by default): launch every Claude session with `--name <tab name>`, not only the ones you renamed, so Claude Code's prompt-box label, `/resume` entry and remote session list read the same as the tab instead of Claude's own generated title. With it off nothing changes. The cost: Claude stops generating its own titles for those sessions, and a rename in Codeman holds only until the next turn (an auto-name reaches the CLI at its next spawn). The setting is read at each session start and respawn, so a toggle applies without a server restart.