test: add peer CLI game directory fixtures

Add three reusable peer CLI game directory fixtures for local smoke tests.
Each fixture is a complete games root that can be passed directly to
--games-dir, with catalog-backed game IDs, version.ini sentinels, and real RAR
archives renamed to .eti.

The fixtures intentionally overlap in two places so multi-peer tests can cover
shared availability. Alpha and bravo both contain ggoo, while bravo and charlie
both contain cnc4. The archives contain generated random payload files rather
than meaningful game data; this keeps the fixtures fake while still exercising
RAR-backed ETI handling.

The tradeoff is committing roughly 34 MiB of binary fixture data. That is
intentional here because the fixtures need real archives for CLI tests instead
of synthetic text placeholders.

Test Plan:
- Ran git diff --check.
- Ran unrar t -idq over every .eti file in the fixture tree.

Refs: none

crates/lanspread-peer-cli/README.md

@@ -18,6 +18,15 @@ Useful flags:
 - `--state-dir PATH` stores the generated peer identity.
 - `--fixture GAME_ID` seeds a tiny archive that the fixture unpacker can install.
 
+## Fixture Game Directories
+
+`fixtures/fixture-alpha`, `fixtures/fixture-bravo`, and
+`fixtures/fixture-charlie` are ready-to-use game directories for local CLI
+smoke tests. Point `--games-dir` at one of them to start a peer with several
+catalog-backed fake games. Each game includes `version.ini` and a real RAR
+archive renamed to `.eti`; `fixture-alpha` and `fixture-bravo` share `ggoo`,
+while `fixture-bravo` and `fixture-charlie` share `cnc4`.
+
 ## Commands
 
 Every command is a JSON object with `cmd` or `command`; `id` is optional and is

crates/lanspread-peer-cli/fixtures/fixture-alpha/alienswarm/notes.txt

@@ -0,0 +1 @@
+extra sibling file for alienswarm

crates/lanspread-peer-cli/fixtures/fixture-alpha/alienswarm/version.ini

@@ -0,0 +1 @@
+20250101

crates/lanspread-peer-cli/fixtures/fixture-alpha/bf1942/version.ini

@@ -0,0 +1 @@
+20250103

crates/lanspread-peer-cli/fixtures/fixture-alpha/ggoo/version.ini

@@ -0,0 +1 @@
+20250102

crates/lanspread-peer-cli/fixtures/fixture-bravo/bfbc2/version.ini

@@ -0,0 +1 @@
+20250201

crates/lanspread-peer-cli/fixtures/fixture-bravo/cnc4/version.ini

@@ -0,0 +1 @@
+20250202

crates/lanspread-peer-cli/fixtures/fixture-bravo/cnctw/version.ini

@@ -0,0 +1 @@
+20250203

crates/lanspread-peer-cli/fixtures/fixture-bravo/ggoo/version.ini

@@ -0,0 +1 @@
+20250102

crates/lanspread-peer-cli/fixtures/fixture-charlie/cnc4/version.ini

@@ -0,0 +1 @@
+20250202

crates/lanspread-peer-cli/fixtures/fixture-charlie/cod5/version.ini

@@ -0,0 +1 @@
+20250301

crates/lanspread-peer-cli/fixtures/fixture-charlie/cod6/version.ini

@@ -0,0 +1 @@
+20250302

crates/lanspread-peer-cli/fixtures/fixture-charlie/coh/version.ini

@@ -0,0 +1 @@
+20250303