Develop: Allow to use internal/tmp/ as scratch space for testing

Signed-off-by: Michael Mayer <michael@photoprism.app>

.dockerignore

@@ -82,3 +82,4 @@ Thumbs.db
 .swp
 .glide
 /tmp/
+/internal/tmp/

.gitignore

@@ -35,6 +35,7 @@ venv
 /pro
 /plus
 /tmp/
+/internal/tmp/
 /test/
 *-lock.json
 /node_modules

AGENTS.md

@@ -1,6 +1,6 @@
 # PhotoPrism® Repository Guidelines
 
-**Last Updated:** October 12, 2025
+**Last Updated:** October 14, 2025
 
 ## Purpose
 
@@ -272,6 +272,7 @@ Note: Across our public documentation, official images, and in production, the c
 ### Testing & Fixtures
 
 - Go tests live next to their sources (`path/to/pkg/<file>_test.go`); group related cases as `t.Run(...)` sub-tests to keep table-driven coverage readable, and name each subtest with a PascalCase string.
+- Keep Go scratch work inside `internal/...`; Go refuses to import `internal/` packages from directories like `/tmp`, so create temporary helpers under a throwaway folder such as `internal/tmp/` instead of using external paths.
 - Prefer focused `go test` runs for speed (`go test ./internal/<pkg> -run <Name> -count=1`, `go test ./internal/commands -run <Name> -count=1`) and avoid `./...` unless you need the entire suite.
 - Heavy packages such as `internal/entity` and `internal/photoprism` run migrations and fixtures; expect 30–120s on first run and narrow with `-run` to keep iterations low.
 - For CLI-driven tests, wrap commands with `RunWithTestContext(cmd, args)` so `urfave/cli` cannot exit the process, and assert CLI output with `assert.Contains`/regex because `show` reports quote strings.

CODEMAP.md

@@ -1,6 +1,6 @@
 PhotoPrism — Backend CODEMAP
 
-**Last Updated:** October 12, 2025
+**Last Updated:** October 14, 2025
 
 Purpose
 - Give agents and contributors a fast, reliable map of where things live and how they fit together, so you can add features, fix bugs, and write tests without spelunking.
@@ -250,6 +250,9 @@ See Also
 - Developer Guide (Setup/Tests/API) — links in AGENTS.md → Sources of Truth
 - Specs: `specs/dev/backend-testing.md`, `specs/dev/api-docs-swagger.md`, `specs/portal/README.md`
 
+Go Internal Import Rule
+- Keep temporary Go helpers inside `internal/...`; the Go toolchain blocks importing `internal/` packages from directories such as `/tmp`, so use a disposable path like `internal/tmp/` when you need scratch space.
+
 Fast Test Recipes
 - Filesystem + archives (fast): `go test ./pkg/fs -run 'Copy|Move|Unzip' -count=1`
 - Media helpers (fast): `go test ./pkg/media/... -count=1`