fix consul engine bug when calling Set and List

[bseto]

This PR fixes two bugs with the Consul Engine Implementation

1. When trying to run the example with consul as the engine, I get an error about the key starting with a /

./_build/kvctl create namespace test-ns
error: Invalid key. Key must not begin with a '/': /kvrocks/metadata/test-ns

2. Listing values from consul only produces 1 character results

./_build/kvctl list namespaces
t 

Setup

# running setup for the consul and other engines
make setup

# on another 3 terminals, I'm running 3 instances of kvrocks
./build/kvrocks -c kvrocks.conf --cluster-enabled yes --port 6001 --dir /tmp/kvrocks1
./build/kvrocks -c kvrocks.conf --cluster-enabled yes --port 6002 --dir /tmp/kvrocks1
./build/kvrocks -c kvrocks.conf --cluster-enabled yes --port 6003 --dir /tmp/kvrocks1

# run kvctl-server with config-consul, with the addr modified:  addr: "127.0.0.1:9379"
./_build/kvctl-server -c config/config-consul.yaml

# BUG 1
./_build/kvctl create namespace test-ns
error: Invalid key. Key must not begin with a '/': /kvrocks/metadata/test-ns

# after fixing bug 1, continuing with the example and listing the namespace
# BUG 2
./_build/kvctl list namespaces
t

[bseto]

Bug 2 fix. I noticed that this was missing the : which I could find in the etcd and other implementations

[bseto]

trimming the leading / to avoid the error
https://github.com/hashicorp/consul/blob/main/api/kv.go#L208-L210

[bseto]

the error really happened because the nsPrefix has a leading /, but I think if we just keep the tests consistent with the other engines and it'll be ok?

[codecov-commenter]

Codecov Report

❌ Patch coverage is 90.90909% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 46.34%. Comparing base (6c56470) to head (3b365b9).
⚠️ Report is 77 commits behind head on unstable.

Files with missing lines	Patch %	Lines
store/engine/consul/consul.go	90.90%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable     #283      +/-   ##
============================================
+ Coverage     43.38%   46.34%   +2.95%     
============================================
  Files            37       45       +8     
  Lines          2971     4296    +1325     
============================================
+ Hits           1289     1991     +702     
- Misses         1544     2097     +553     
- Partials        138      208      +70     

Flag	Coverage Δ
unittests	46.34% <90.90%> (+2.95%)	⬆️

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[git-hulk]

@bseto Great! Thanks for your fix, will have a look soon.

[Copilot]

Pull Request Overview

This PR fixes two critical issues in the Consul engine implementation: ensuring that keys do not start with a leading slash and correcting the key trimming logic in the List function to return complete namespace names.

• Updated Consul configuration to point to the correct Consul agent address.
• Modified engine methods (Get, Exists, Set, Delete, List) to sanitize keys using a new helper function.
• Adjusted tests to provide keys with a leading slash, verifying that key sanitization works as expected.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
config/config-consul.yaml	Updated Consul address to match test setup requirements.
store/engine/consul/consul.go	Introduced key sanitization in Consul methods and fixed key slicing in List.
store/engine/consul/consul_test.go	Modified test keys to include a leading slash to trigger sanitization.