fix(snapshot): catch httpx transport errors in --estimate path

CI failure: test_readers_in_pre_init_dir asserted no Traceback in stderr
when running `agnes snapshot create x --as y --estimate` in a folder
that never saw `agnes init`. The estimate-guard fix in 3d587681 let
`--estimate` skip the local_db check and reach `api_post_json`, but the
existing `except V2ClientError` doesn't cover transport-layer failures.
With no server configured the URL defaults to http://localhost:8000;
httpx raises ConnectError → ConnectError isn't a V2ClientError → the
exception bubbles up through Typer/rich as a full traceback.

Add `except httpx.HTTPError` next to V2ClientError so connection /
DNS / TLS / timeout failures all render the friendly hint
`Run `agnes init …` first` instead of leaking transport noise.

CHANGELOG.md

@@ -38,6 +38,7 @@ End-to-end clean-analyst-bootstrap rewrite. The web `/setup?role=analyst` page n
 - `agnes snapshot create` (formerly `da fetch`) no longer materializes an empty `user/duckdb/analytics.duckdb` when run before any `agnes pull`. Friendly hint redirects to `agnes pull`.
 - Workspace `agnes status` reads from the canonical `server/parquet/` and `user/duckdb/analytics.duckdb` paths (was reading legacy `data/parquet/`, `data/metadata/last_sync.json`).
 - `agnes init` and `agnes pull` errors now use the `cli/error_render.py` typed-error renderer (added in 0.32.0), so analyst-facing error UX matches the structured shape `agnes query --remote` already produces.
+- `agnes snapshot create … --estimate` in a pre-init directory no longer leaks an httpx `ConnectError` traceback to stderr. The estimate-guard fix (3d587681) let `--estimate` reach `api_post_json`, but the existing `except V2ClientError` clause didn't catch transport-layer errors when no server was configured (defaulted to `http://localhost:8000`). Now also catches `httpx.HTTPError` and renders the friendly hint `Run \`agnes init …\` first`.
 - `agnes push` now reads Claude Code session jsonls from `~/.claude/projects/<encoded-cwd>/` (where Claude Code actually writes them), instead of `<workspace>/user/sessions/` (which the SessionEnd hook never populated — the previous code uploaded an empty list every time). Encoding logic in `cli/lib/claude_sessions.py` probes both Claude Code variants — older `/`→`-` and newer all-non-alphanumeric→`-` — and unions the result, so users who have upgraded Claude Code mid-project see sessions from both encoded dirs. Falls back to `<workspace>/user/sessions/` for back-compat.
 
 ### Removed

cli/commands/snapshot.py

@@ -8,6 +8,7 @@ from datetime import datetime, timedelta, timezone
 from pathlib import Path
 
 import duckdb
+import httpx
 import pyarrow.parquet as pq
 import typer
 
@@ -272,6 +273,17 @@ def create_cmd(
         except V2ClientError as e:
             typer.echo(f"Error: estimate failed: {e}", err=True)
             raise typer.Exit(_exit_code_for(e))
+        except httpx.HTTPError as e:
+            # Connection refused / DNS / TLS / timeout — friendly render so
+            # `agnes snapshot create … --estimate` in a pre-init dir (no
+            # server configured, defaults to http://localhost:8000) prints
+            # a hint instead of leaking an httpx traceback to stderr.
+            typer.echo(
+                f"Error: could not reach server ({e.__class__.__name__}). "
+                f"Run `agnes init --server-url <url> --token <pat>` first.",
+                err=True,
+            )
+            raise typer.Exit(7)
         typer.echo(f"Estimate for {table_id}:")
         _print_estimate(est)
     if estimate: