docs: use real ~/.claude/projects/ path in first-run help and README (#996)

The CLI help text and README told first-time users to mine from ~/chats/,
a path that doesn't exist on any machine. Real location where Claude
Code writes session JSONL is ~/.claude/projects/<escaped-project-path>/.

Updates three user-visible strings:
- mempalace/cli.py line 7 ("Two ways to ingest" block)
- mempalace/cli.py line 25 (Examples block)
- README.md line 58 (Quickstart)

Website guides (website/guide/mining.md, getting-started.md) still
reference ~/chats/ for ChatGPT/Slack export scenarios where that remains
a valid placeholder. Those can be a separate PR if the maintainers want
to tilt the website examples toward Claude Code specifically.

Fixes #996.

README.md

@@ -55,7 +55,7 @@ mempalace init ~/projects/myapp
 ```bash
 # Mine content into the palace
 mempalace mine ~/projects/myapp                    # project files
-mempalace mine ~/chats/ --mode convos              # conversation exports
+mempalace mine ~/.claude/projects/ --mode convos   # Claude Code sessions (scope with --wing per project)
 
 # Search
 mempalace search "why did we switch to GraphQL"

mempalace/cli.py

@@ -4,7 +4,7 @@ MemPalace — Give your AI a memory. No API key required.
 
 Two ways to ingest:
   Projects:      mempalace mine ~/projects/my_app          (code, docs, notes)
-  Conversations: mempalace mine ~/chats/ --mode convos     (Claude, ChatGPT, Slack)
+  Conversations: mempalace mine <convo-dir> --mode convos     (Claude Code, Claude.ai, ChatGPT, Slack exports)
 
 Same palace. Same search. Different ingest strategies.
 
@@ -22,7 +22,7 @@ Commands:
 Examples:
     mempalace init ~/projects/my_app
     mempalace mine ~/projects/my_app
-    mempalace mine ~/chats/claude-sessions --mode convos
+    mempalace mine ~/.claude/projects/-Users-you-Projects-my_app --mode convos --wing my_app
     mempalace search "why did we switch to GraphQL"
     mempalace search "pricing discussion" --wing my_app --room costs
 """