Settle discovery slug and custom path rules

docs/roadmap/discovery.md

@@ -1,10 +1,8 @@
 # Composable Configuration Discovery Roadmap
 
-Status: proposal with the agreed direction, filename groups, and search presets
-captured below. Remaining behavioral choices are under
-[Open Decisions](#open-decisions).
+Status: proposal with OD-1 through OD-5 settled and integrated below.
 This document describes future work, not an implemented contract. A staged
-implementation plan will follow once the decisions are settled.
+implementation plan will follow review of the complete roadmap.
 
 ## Purpose And Ownership
 
@@ -280,6 +278,24 @@ represent both intentions clearly. Presets retain their specified filename group
 Selecting a single preset keeps the simple case concise. Search-wide requiredness
 provides the check for consumers that must find a configuration file.
 
+### Slugs And Custom Path Interpretation (OD-5 — Settled)
+
+Require a nonempty single-component application slug whenever a selected search
+uses it to construct a directory or filename. Reject path separators, `.` and
+`..`, and forms unusable as that component on the target platform. Preserve
+spelling and case; do not trim, lowercase, or impose a kebab-case naming scheme.
+Validation keeps the slug from changing the intended directory structure without
+imposing a separate naming style.
+
+Searches that do not use the slug do not require one. Examples include explicit
+file candidates and a custom directory searched with only Generic filenames.
+
+Treat custom paths as literal host paths. Resolve relative paths against the
+working directory at load time. Do not expand shell variables, `~`, or wildcard
+syntax. Consumers can construct expanded paths themselves; User and Home presets
+provide the common directory-resolution conveniences. These rules keep custom
+paths consistent with explicit file loading.
+
 ### Placement, Provenance, And Existing Features
 
 The selected file participates as the actual file source. Preserve its physical
@@ -320,6 +336,7 @@ The subsequent implementation plan should cover:
   group precedence, the Unix system preset's 14 candidates and named-only `/etc`
   search, custom-list composition, both filename extensions, no-match behavior,
   empty components and searches, omitted versus empty filename selections,
+  slug-dependent and slug-independent searches, literal custom paths,
   required searches, unavailable preset bases, errors that must stop fallback,
   repeated loads, and untouched explicit `File`
   behavior. Cover imports, overlays, underlays, defaults, CLI, source versions,
@@ -334,26 +351,3 @@ The subsequent implementation plan should cover:
 This roadmap does not change implementation, policy, or ADRs by itself. Coordinate
 implementation with the ongoing sequence integration audit rather than assuming
 its in-progress changes are part of a fixed implementation baseline.
-
-## Open Decisions
-
-### OD-5 — Slugs And Custom Path Interpretation
-
-**Recommendation:** require a nonempty single-component slug when a selected
-preset uses it to construct filenames. Reject path separators, `.` and `..`,
-and other forms that cannot be used as that component on the target platform.
-Preserve spelling; do not silently lowercase, trim, or impose a kebab-case naming
-scheme. A composition made only of explicit custom paths need not require an
-application slug.
-
-Treat custom paths as literal host file paths. Resolve relative paths against
-the working directory at load time; do not expand shell variables, `~`, or glob
-syntax. Consumers can construct expanded paths themselves. Selected presets
-provide the convenience for user and working-directory bases.
-
-**Alternative:** require a restricted portable slug grammar, such as lowercase
-ASCII letters, digits, and hyphens. This is easy to document and portable, but
-unnecessarily excludes otherwise usable application names. Automatic shell-like
-custom-path expansion is also viable, but adds escaping and environment semantics
-that ordinary `File(path)` does not supply. Literal paths keep both interfaces
-consistent.