[Bug]: `copy . .` (in lower case) does not copy anything

[0f-0b]

I have done the following

• I have searched the existing issues
• If possible, I've reproduced the issue using the 'main' branch of this project

Steps to reproduce

Create a Dockerfile with the following content (note that copy is in lower case), and then run container build.

from debian:stable-slim
workdir /build
copy . .
run cat Dockerfile

Current behavior

The build fails with cat: Dockerfile: No such file or directory.

Expected behavior

The build succeeds.

Environment

- OS: macOS 26.2 (25C56)
- Xcode: Not installed
- Container: container CLI version 0.8.0 (installed from Homebrew)

Relevant log output

[+] Building 1.1s (7/7) FINISHED                                                                                                                       
 => [resolver] fetching image...docker.io/library/debian:stable-slim                                                                              0.0s
 => [internal] load .dockerignore                                                                                                                 0.0s
 => => transferring context: 2B                                                                                                                   0.0s
 => oci-layout://docker.io/library/debian:stable-slim@sha256:ed542b2d269ff08139fc5ab8c762efe8c8986b564a423d5241a5ce9fb09b6c08                     0.8s
 => => resolve docker.io/library/debian:stable-slim@sha256:ed542b2d269ff08139fc5ab8c762efe8c8986b564a423d5241a5ce9fb09b6c08                       0.0s
 => => sha256:4107269d32a679840c1eb0cd8d8925b7a6c7cba09640d07b8c96ab4fe7cbbca9 30.13MB / 30.13MB                                                  0.3s
 => => extracting sha256:4107269d32a679840c1eb0cd8d8925b7a6c7cba09640d07b8c96ab4fe7cbbca9                                                         0.5s
 => [internal] load build context                                                                                                                 0.0s
 => => transferring context: 2B                                                                                                                   0.0s
 => [linux/arm64/v8 1/4] WORKDIR /build                                                                                                           0.2s
 => [linux/arm64/v8 2/4] COPY . .                                                                                                                 0.0s
 => ERROR [linux/arm64 3/4] RUN cat Dockerfile                                                                                                    0.1s
------
 > [linux/arm64 3/4] RUN cat Dockerfile:
0.056 cat: Dockerfile: No such file or directory
------
Error: unknown (2): failed to solve: process "/bin/sh -c cat Dockerfile" did not complete successfully: exit code: 1

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