Render ini config files from an ordered list, and collapse the two ini renderers into one - #945

Part 1 of 2 for #944.

rstudio-library's ini helpers rendered a config file from a map, and Go templates iterate maps in sorted key order. For files whose behavior depends on the order of their sections or entries — /etc/rstudio/profiles, launcher.*.profiles.conf, launcher.*.resources.conf, repos.conf — that silently changes what the file does, and nothing in values.yaml shows it.

Part 2 (#953) bumps rstudio-workbench onto this, adds the deprecation warning, and updates the docs. It has to wait until rstudio-library 0.1.38 is published, since consumers resolve the library from helm.rstudio.com rather than the working tree.

The ordered form

A file's contents may now be a list, rendered in the order written:

config:
  server:
    profiles:
      - "*":
          max-memory-mb: 1024
      - "@analysts":
          max-memory-mb: 4096
  session:
    repos.conf:
      - Internal: https://pkgs.example.com/internal
      - CRAN: https://packagemanager.posit.co/cran/latest

Previously a list rendered broken lines like *=map[max-memory-mb:1024], with no section headers at all.

Each entry holds exactly one key. That key names a [section] when its value is a map, and an entry when it is not. An entry with more than one key, or none, is rejected — the shapes those produced were all unusable, and the error names the keys and shows where the - goes.

A value is a single value, or a list of them. A list is comma-joined, which is how these files express several values for one option: /etc/rstudio/profiles has cpu-affinity and the AI provider allow/deny lists, launcher.*.profiles.conf has resource-profiles. A map has no representation — ini files have no nesting — and neither does a list holding maps or lists; both fail.

At a file's top level, a list of maps still means several sections with the same name (launcher.conf's cluster:), unchanged.

A raw string is still passed through verbatim.

Collapsing the two ini renderers

profiles.ini was a fork of config.ini that added comma-joining and the job-json-overrides encoding. That split meant the same YAML rendered differently depending on which file it was in — a list as an option's value comma-joined under config.profiles and was rejected under config.server.

Both behaviors moved where they belong:

• Comma-joining is in config.ini, at every depth, as above. It is a property of these file formats, not of one file.
• The job-json-overrides encoding moved out of the renderer into apply-everyone-and-default-to-others, which already rewrote those entries to add their file key. It is a chart-level idea, not an ini one, so the renderer now only ever sees single values.

With both in place, profiles.ini.singleFile, the old multi-file profiles.ini, and collapse-array are removed, and profiles files render through config.ini like every other ini file.

Breaking

• rstudio-library.profiles.ini.advanced is renamed to rstudio-library.profiles.ini — it is the only profiles helper now, so "advanced" meant nothing. Consumers update their include when they adopt 0.1.38. rstudio-connect pins 0.1.36 and is unaffected until it bumps; if missed, the failure is loud (no template … associated), not silent.
• apply-everyone-and-default-to-others takes a file key and renders the whole file, rather than its caller emitting the name: | header.
• A list of values no longer produces repeated keys at a file's top level; it is comma-joined. No chart default, lint/, or ci/ file in this repo uses that shape, and rserver.conf's option schema has no list-typed options. chronicle-local.gcfg is the one format that genuinely supports repeated keys, but it cannot express them through this renderer today either — see chronicle-local.gcfg is rendered as ini, and its values are never quoted #954.
• A map as an option's value now fails rather than rendering key=map[a:1]. Confirmed harmless for Chronicle, whose config struct has no map[...] field and therefore no gcfg subsections.

Testing

other-charts/rstudio-library-test covers, for config.ini and the profiles helpers:

• the list form for each order-sensitive file — sections and entries in order, with headers where the file has them
• the map form — sorted by name, as before
• the raw string form — verbatim
• comma-joining, at both depths
• repeated section names (launcher.conf's cluster:)
• job-json-overrides merging and the JSON payloads it generates
• every rejected shape: multi-key entry, empty entry, non-map entry, map as a value, list holding a map

94 tests pass. Rendering every values file under charts/*/lint/ and charts/*/ci/ is unchanged except where a previously-broken shape now renders correctly.