bug: preserve distinct application identities in default configuration directories

[codeforester]

Goal

Keep the default user configuration of distinct explicitly named applications isolated.

Background and reproduction

Release review of 3253c10975ac674eb2e79c146bb7729d5c4cb251; reproduced on macOS arm64 with Python 3.13.15.

Both CliProfile.batteries_included and BatteriesIncludedConfigLoader call normalize_cli_name, which treats the identity as a program filename and removes its final dotted component. The public App identity and runtime namespaces preserve those components. As a result acme.tools, acme.deploy, and acme all read <config-root>/acme/config.yaml, even though they are distinct application identities with separate runtime directories. Space replacement and basename extraction introduce further collisions.

Harmless public-API reproduction:

from pathlib import Path
from tempfile import TemporaryDirectory
from base_cli import CliProfile

with TemporaryDirectory() as tmp:
    root = Path(tmp)
    (root / "acme").mkdir()
    (root / "acme/config.yaml").write_text("service: shared-from-acme\n")
    for name in ("acme.tools", "acme.deploy", "acme"):
        profile = CliProfile.batteries_included(name, config_root=root)
        print(name, profile.load_config(None, None).config)

All three print {'service': 'shared-from-acme'}. Direct loaders for the first two names also expose the same user_config_path. This can silently select another application's endpoints or settings.

local-config.md promises an isolated directory selected by the identity. The regression added for #313 only compares Alpha Tool and beta, so it misses identity collisions. This is a remaining isolation gap after #313, distinct from ancestor-project trust in #385.

Source: profile factory, loader, filename normalization.

Scope and acceptance criteria

• Use an explicit-identity namespace policy in both public entry points that preserves distinct supported identities and cannot escape the config root. Reuse the runtime namespace policy where appropriate.
• Cover dotted names, space/hyphen collisions, unsafe path characters, and ordinary existing names through loader and profile APIs.
• Keep explicit user_config_dir authoritative, including intentional sharing.
• Document the resulting path contract and compatibility/migration treatment; do not silently merge or automatically move existing config directories.

Validation

Run the public reproducer, focused configuration/identity tests, generated documentation checks, strict typing, and tests/full_validate.sh.

Non-goals

No release publication, unrelated API redesign, or changes to consumer workspaces.

Project fields

• Status: Ready
• Priority: P2
• Area: Python
• Initiative: Adoption Polish
• Size: M
• Milestone: v0.5.0

Agent assignment

Assignee: @codeforester. Implement through the normal issue-backed worktree and reviewed PR workflow.