feat: clarify account history sync route (#1187)

* feat: clarify account history sync route

* fix: clarify shared context command examples

* fix: report missing bare profile settings

docs/session-sharing-technical-analysis.md

@@ -1,6 +1,6 @@
 # Session Sharing Technical Analysis
 
-Last Updated: 2026-04-04
+Last Updated: 2026-05-05
 
 ## Summary
 
@@ -12,6 +12,38 @@ This is implemented as a context policy per account:
 - `shared` + `standard` (default): account workspace context is linked to a shared context group
 - `shared` + `deeper` (advanced opt-in): account also shares continuity artifacts
 
+## Recommended Two-Account Route
+
+Use `ccs auth` account profiles when you want two real Claude accounts and want to choose which one runs each session:
+
+```bash
+ccs auth create work
+ccs auth create personal
+
+ccs work
+ccs personal
+```
+
+This keeps usage and credentials isolated. Each account owns its own Claude config directory, login state, and `.anthropic` credentials.
+
+Basic Claude settings are shared for non-bare account profiles:
+
+```text
+~/.ccs/instances/<account>/settings.json
+  -> ~/.ccs/shared/settings.json
+  -> ~/.claude/settings.json
+```
+
+This is for ordinary Claude Code settings, hooks, commands, skills, agents, and plugins. It is not token sharing. `ccs auth show <account>` reports the current `Settings`, `History`, and `Plain ccs` lanes so users can see whether settings and resume history are aligned.
+
+Only opt in to shared history when both accounts should see the same local continuity:
+
+```bash
+ccs auth create work2 --share-context --context-group daily --deeper-continuity
+```
+
+For existing accounts, use Dashboard -> Accounts -> Sync on both accounts, set both to `shared`, and use the same `History Sync Group`. Use `deeper` only when users expect stronger local handoff beyond project context.
+
 ## Why This Is Safe Enough
 
 CCS only shares workspace context paths (project/session context files). It does **not** merge or copy authentication credentials between accounts.
@@ -93,14 +125,24 @@ continuity:
     default: work
 ```
 
+Example with an existing `ck` account:
+
+```bash
+ccs auth show ck
+ccs auth backup default
+ccs auth default ck
+```
+
+`ccs auth default ck` makes future plain `ccs` sessions use the `ck` account lane, so future `ccs` and `ccs ck` resume from the same local inventory. It does not automatically import old native `~/.claude/projects` history into `ck`; keep using `ccs -r` for the old native lane until you intentionally migrate that local history.
+
 ## User Workflows
 
 ### New account with shared context
 
 ```bash
 ccs auth create work2 --share-context
-ccs auth create backup --context-group sprint-a
-ccs auth create backup2 --context-group sprint-a --deeper-continuity
+ccs auth create backup --share-context --context-group sprint-a
+ccs auth create backup2 --share-context --context-group sprint-a --deeper-continuity
 ```
 
 ### Existing account