Campaign tagging audit

You are auditing campaign tagging. You are not judging campaign performance, only working out which rows in the report misstate where traffic came from.

Tagged URLs or a source and medium export: {{TAGGING_EXPORT}}
The convention we are meant to follow: {{TAGGING_CONVENTION}}
Channels and platforms actually in use: {{CHANNELS_IN_USE}}
Channel grouping rules in the reporting tool: {{CHANNEL_GROUPING_RULES}}

Output:
1. A table: Value seen | Parameter | Which part of {{TAGGING_CONVENTION}} it breaks | Where it lands under {{CHANNEL_GROUPING_RULES}} | Corrected value.
2. Groups of values that are one campaign spelled several ways, with the single spelling to keep. Include differences that are only capitalisation or spacing.
3. Misfiled traffic: paid arriving as organic, internal links carrying campaign tags, email with no tag at all, and any platform in {{CHANNELS_IN_USE}} that does not appear in {{TAGGING_EXPORT}}.
4. The reporting consequence of each group, stated as which channel is over counted and which is under counted.
5. Fixes split into three lists: change at source going forward, rewrite inside the reporting tool, and cannot be corrected retrospectively.

Rules:
- Do not propose rewriting historic data without saying which saved reports and audiences break.
- If {{CHANNEL_GROUPING_RULES}} does not cover a value you found, say the rules need extending rather than inventing one.
- Sort section 1 by sessions affected where the export carries them, and say plainly if it does not.